State determination device, state determination system, and state determination method

Abstract

This technology provides a way to determine the state of an object being measured with greater accuracy. [Solution] The state determination device comprises a state index generation unit 24 that generates a state index for determining the state of an object to be measured based on a spectral spectrum obtained from electromagnetic waves transmitted through or reflected by the object to be measured after electromagnetic waves are irradiated onto the object to be measured, and a state determination unit 26 that determines the state of the object to be measured based on the state index of the object to be measured. The state index generation unit 24 generates a state index using the intensity of the spectral spectrum in a frequency range unaffected by peaks, generates a state index for the object to be measured after applying a correction to the spectral spectrum to reduce the effect of peaks, or generates a state index based on a plurality of frequencies extracted at frequency intervals narrower than the width of the peaks.

Description

Technical Field

[0001] The present disclosure relates to a state determination device, a state determination system, and a state determination method.

Background Art

[0002] Patent Document 1 discloses a technique in which an object to be measured is irradiated with electromagnetic waves, electromagnetic waves transmitted or reflected by the object to be measured are detected, a spectral spectrum of the object to be measured is generated from the detected electromagnetic waves, a state index of the object to be measured is generated based on the generated spectral spectrum, and the state of the object to be measured is determined based on the state index. According to Patent Document 1, the state of the object to be measured can be determined nondestructively.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology as described in Patent Document 1, the state index is affected by peaks derived from photon vibrations of molecules or crystals of the object to be measured.

[0005] The present disclosure has been made in view of such a situation, and an exemplary object of one aspect thereof is to provide a technique capable of more accurately determining the state of an object to be measured.

Means for Solving the Problems

[0006] To solve the above problems, a state determination device in one embodiment of the present disclosure includes a state index generation unit that generates a state index for determining the state of an object to be measured based on a spectral spectrum obtained from electromagnetic waves transmitted through or reflected by an object to be measured after the object to be measured is irradiated with electromagnetic waves, and a state determination unit that determines the state of an object to be measured based on the state index of the object to be measured. The state index generation unit generates a state index using the intensity of the spectral spectrum in a frequency range unaffected by peaks, generates a state index for an object to be measured after applying a correction to the spectral spectrum to reduce the effect of peaks, or generates a state index based on the intensity of the spectral spectrum at a plurality of frequencies extracted at frequency intervals of 1 / 2 or less of the peak width.

[0007] Another aspect of the present disclosure is a state determination system. This system comprises an irradiation unit that irradiates an object to be measured with electromagnetic waves, a detection unit that detects electromagnetic waves that have passed through or been reflected by the object to be measured, and the state determination device described above.

[0008] Another aspect of this disclosure is a determination method. This method is a determination method for determining the state of an object to be measured, comprising: irradiating the object to be measured with electromagnetic waves; detecting electromagnetic waves transmitted through or reflected by the object to be measured; generating a state index for determining the state of the object to be measured based on a spectral spectrum obtained from the detected electromagnetic waves; and determining the state of the object to be measured based on the state index of the object to be measured. In generating the index, the method involves generating a state index using the intensity of the spectral spectrum in a frequency range unaffected by peaks, generating a state index for the object to be measured after applying a correction to the spectral spectrum to reduce the effect of peaks, or generating a state index based on the intensity of the spectral spectrum at multiple frequencies extracted at frequency intervals of 1 / 2 or less of the peak width.

[0009] Furthermore, any combination of the above components, or any substitution of the components or expressions of this disclosure between methods, apparatus, systems, etc., is also valid as a form of this disclosure. [Effects of the Invention]

[0010] This disclosure provides a technology that can determine the state of an object being measured with greater accuracy. [Brief explanation of the drawing]

[0011] [Figure 1] This diagram shows the schematic configuration of the state determination system according to the embodiment. [Figure 2] Figure 1 is a block diagram showing the functions and configuration of the state determination device. [Figure 3] This figure shows an example of the spectral spectrum of an object being measured. [Figure 4] This figure shows the spectral spectrum obtained by applying a single smoothing process to the spectral spectrum of Figure 3. [Modes for carrying out the invention]

[0012] Preferred embodiments will be described below with reference to the drawings. These embodiments are illustrative and not limiting to the disclosure, and not all features or combinations thereof described in the embodiments are necessarily essential to the disclosure. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0013] Figure 1 is a diagram showing the schematic configuration of the state determination system 1 according to an embodiment. The state determination system 1 is a system that determines the state of the object OBJ under measurement.

[0014] The object under test (OBJ) is not particularly limited, but may be a polymer material such as resin or rubber. The resin may be a polyolefin resin such as polyethylene or polypropylene. The object under test (OBJ) may be the material before processing such as molding or kneading, or it may be a molded product after processing.

[0015] In this embodiment, the state of the measurement object OBJ is the state of the measurement object OBJ regarding deterioration, for example, the state of the characteristics of the measurement object OBJ that change due to deterioration. As an example, when the measurement object OBJ is a resin, the characteristic is the melt viscosity of the measurement object OBJ.

[0016] The state determination system 1 includes an irradiation unit 10, a detection unit 12, and a state determination device 14. The irradiation unit 10 and the detection unit 12 are connected to the state determination device 14.

[0017] The irradiation unit 10 irradiates the measurement object OBJ with the electromagnetic wave W1. The detection unit 12 detects the electromagnetic wave W2 obtained as a result of irradiating the measurement object OBJ with the electromagnetic wave W1. The electromagnetic wave W2 may be the electromagnetic wave W2 that has passed through the measurement object OBJ as shown in the figure. Alternatively, the electromagnetic wave W2 may be the electromagnetic wave W2 reflected by the measurement object OBJ. The detection result of the electromagnetic wave W2 generated by the detection unit 12 is supplied to the state determination device 14.

[0018] The state determination device 14 generates a spectral spectrum based on the relationship between the electromagnetic wave W1 irradiated by the irradiation unit 10 and the electromagnetic wave W2 detected by the detection unit 12. In this embodiment, the spectral spectrum is a spectrum of absorbance. Note that the spectral spectrum may be a spectrum of transmittance, reflectance, or phase difference. The state determination device 14 determines the state of the measurement object OBJ based on the spectral spectrum.

[0019] The electromagnetic wave W1 is an electromagnetic wave capable of determining the state of the measurement object OBJ. The electromagnetic wave W1 may be an electromagnetic wave in a frequency region related to the vibration of polymer chains and crystal lattices, for example, an electromagnetic wave in the terahertz region of 1 THz to 2 THz, or alternatively, an electromagnetic wave in the infrared region.

[0020] FIG. 2 is a block diagram showing the functions and configuration of the state determination device 14. Each block shown in FIG. 2 can be realized hardware-wise by elements and electronic circuits such as a computer's processor, CPU, memory, and mechanical devices, and software-wise by a computer program or the like. Here, however, functional blocks realized by their cooperation are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by combinations of hardware and software.

[0021] The state determination device 14 includes an irradiation control unit 20, a spectral spectrum generation unit 22, a state index generation unit 24, a state determination unit 26, and a storage unit 28. The storage unit 28 stores information used by the state determination device 14.

[0022] The irradiation control unit 20 controls the irradiation unit 10. The irradiation control unit 20 controls the on / off of the irradiation unit 10, that is, the irradiation timing of electromagnetic waves and the like.

[0023] The spectral spectrum generation unit 22 generates the spectral spectrum of the object to be measured OBJ from the electromagnetic wave W2 detected by the detection unit 12. FIG. 3 is a diagram showing an example of the spectral spectrum of the object to be measured OBJ. The spectral spectrum generation unit 22 may apply a smoothing process to the spectral spectrum. FIG. 4 is a diagram showing the spectral spectrum obtained by applying one smoothing process to the spectral spectrum of FIG. 3.

[0024] The state index generation unit 24 generates a state index, which is an index for determining the state of the object to be measured OBJ, based on the spectral spectrum of the object to be measured OBJ generated by the spectral spectrum generation unit 22. Here, the spectral spectrum tends to increase or decrease monotonically as the frequency increases. Also, the spectral spectrum tends to have a greater slope as the deterioration of the object to be measured OBJ progresses. Therefore, the state of deterioration of the object to be measured OBJ can be determined from the magnitude of the slope of the spectral spectrum of the object to be measured OBJ, or the height of the intensity of the spectral spectrum in a specific frequency or frequency range. What to use as the state index may be determined in consideration of this.

[0025] In this embodiment, although not particularly limited, the state index may be any of the following state indexes 1 to 5.

[0026] State index 1: Intensity of the spectral spectrum at a specific frequency. State index 2: The first derivative of the spectral spectrum at a specific frequency. State index 3: Change in the spectral spectrum within a specific frequency range State index 4: The average intensity of the spectral spectrum in a specific frequency range. State Index 5: Average value of the first derivative of the spectral spectrum in a specific frequency range.

[0027] The change in state index 3 can be calculated using known or future available technologies. For example, the change in state index 3 may be calculated by fitting a straight line.

[0028] Regardless of the performance of the detection unit 12, there are limitations to the detectable frequency range, albeit to varying degrees. The signal-to-noise ratio (S / N ratio) becomes extremely low in the low frequency range (below 1 THz in the example in Figure 4) and the high frequency range (above 2.8 THz in the example in Figure 4). Therefore, these frequency ranges are excluded regardless of which state indicator is used.

[0029] The state index generation unit 24 may generate state indices 1 to 5 of the object OBJ under test using only the frequency range unaffected by peaks (hereinafter simply referred to as peaks) in the spectral spectrum that originate from photon vibrations. The frequency range unaffected by peaks may be the frequency range excluding the peak frequency range R1. If the spectral spectrum has a frequency range R2 adjacent to the higher frequency side of the peak frequency range R1, as in the example in Figure 4, where the intensity drops significantly, the frequency range unaffected by peaks may be the frequency range excluding both frequency ranges R1 and R2. Note that frequency range R1 is the same as or wider than frequency range R2. When generating state index 3, the state index generation unit 24 may generate it using both frequencies in a frequency range lower than frequency range R1 and frequencies in a frequency range higher than frequency range R1 if the spectral spectrum does not have frequency range R2, or it may generate it using both frequencies in a frequency range lower than frequency ranges R1 and R2 and frequencies in a frequency range higher than frequency ranges R1 and R2 if the spectral spectrum has frequency range R2.

[0030] The frequency ranges R1 and R2 may be determined from literature. The frequency ranges R1 and R2 may also be determined by conducting experiments in advance. The frequency ranges R1 and R2 may also be determined by analyzing the spectral data using known or future available techniques. For example, the frequency range R1 may be a frequency range where the lower and upper limits are the frequencies of the maximum and minimum points of the first derivative spectrum obtained by taking the first derivative of the spectral data, respectively.

[0031] The state index generation unit 24 may apply a correction to the portion of the spectral spectrum that contains a peak, thereby reducing the influence of that peak, i.e., removing the peak. This correction can be implemented using known or future available technologies. In this case, the state index generation unit 24 may generate state indices 1 to 5 using frequencies in the frequency range where there was a peak before correction, in addition to or instead of frequencies in the frequency range where there was no peak before correction.

[0032] The state index generation unit 24 may smooth the spectral spectrum to the extent that the influence of peaks is eliminated. For example, the state index generation unit 24 may apply a predetermined number of smoothing processes (e.g., 10 times) to the spectral spectrum to eliminate the influence of peaks. Known techniques may be used for the smoothing process. When the spectral spectrum is smoothed, the state index generation unit 24 may generate state indices 1 to 5 using frequencies in the frequency range where peaks existed before smoothing.

[0033] The state index generation unit 24 may calculate the state index 5 based on the intensity of the spectral spectrum at multiple frequencies extracted from the spectral spectrum at frequency intervals of 1 / 2 or less of the peak width, i.e., the width of the frequency range R1, for example, at a frequency interval of 0.1 THz. In this case, the state index generation unit 24 may calculate the state index 5 based on the intensity of the spectral spectrum at multiple frequencies including the frequencies of the frequency range R1, or the intensity of the spectral spectrum at multiple frequencies including the frequencies of the frequency ranges R1 and R2. Here, of the frequency range R1 of the peaks of the spectral spectrum, the first derivative value is positive for the frequency range R1a from the beginning of frequency range R1 to the vertex of the upward-convex curve, and the first derivative value is negative for the frequency range R1b from the vertex to the end of frequency range R1. Also, if the spectral spectrum has a frequency range R2 as in the example in Figure 4, of the frequency range R2, the first derivative value is negative for the frequency range R2a from the beginning of frequency range R2 to the vertex of the downward-convex curve, and the first derivative value is positive for the frequency range R2b from the vertex to the end of frequency range R2. The widths of the frequency ranges R1a, R1b, R2a, and R2b are generally less than or equal to half the width of the peak. Therefore, when multiple frequencies are extracted at frequency intervals of less than or equal to half the width of the peak, the spectral intensity of the spectral spectrum of the frequency range R1b is included in addition to the spectral intensity of the spectral spectrum of the frequency range R1a, or the spectral intensity of the spectral spectrum of the frequency ranges R1b and R2b is included in addition to the spectral intensity of the spectral spectra of the frequency ranges R1a and R2a, resulting in the effects of the peaks canceling each other out.

[0034] The state determination unit 26 determines the state of the object under measurement OBJ based on the state index of the object under measurement OBJ generated by the state index generation unit 24. The state determination unit 26 may be capable of executing at least one of the first determination process and the second determination process as the process for determining the state of the object under measurement OBJ.

[0035] The first determination process is a process that determines (identifies) the state of the object under measurement (OBJ) based on relational information that represents the relationship between the state index of the reference object and the state of the reference object.

[0036] For example, the memory unit 28 may store a function (arithmetic expression) as relational information that represents the relationship between the state index of the reference object and the state of the reference object, and the state determination unit 26 may, as the first process, determine the state of the object OBJ by substituting the state index of the object OBJ to be measured into this function and performing an operation.

[0037] Alternatively, for example, the memory unit 28 may store a lookup table as relational information that defines the relationship between the state index of the reference object and the state of the reference object, and the state determination unit 26 may, as a first process, determine the state of the object OBJ to be measured by referring to this lookup table.

[0038] When the object OBJ to be measured is a resin, the state of the object OBJ determined in the first determination process may be the melt viscosity of the object OBJ with respect to temperature. In this case, state indices are generated in advance for reference materials of various degrees of degradation, and the melt viscosity is measured, and the relationship information between the state indices and melt viscosity is stored in the storage unit 28. The state indices can be generated using the state determination system 1. The melt viscosity can be measured using a device such as a capillary rheometer. The melt viscosity can be used, for example, to understand the degradation state and sort the object OBJ before processing, to determine the mixing conditions for kneading using that material, or to determine the molding conditions for molding using that material.

[0039] When the object under test (OBJ) is a resin, the state of the object under test determined in the first determination process may be the melt flow rate (MFR) or the molecular weight of the object under test. These may vary depending on, for example, the degree of degradation of the object under test.

[0040] The state of the object OBJ determined in the first determination process may be the state of the object OBJ that can be evaluated in a tensile test, specifically the tensile strength, stress, yield point, elongation, or strain of the object OBJ.

[0041] The state of the object's OBJ determined in the first determination process may be the state of the object's OBJ that can be evaluated by a Charpy impact test, specifically the impact resistance or toughness of the object's OBJ.

[0042] The state of the object OBJ determined in the first determination process may be the bending strength, bending strain, or bending modulus of the object OBJ that can be evaluated in the bending test.

[0043] Regardless of which state is being determined, tests and other methods should be conducted to prepare in advance relational information that shows the relationship between the state index and the state of the reference material.

[0044] The second determination process is a process that determines the state of the object under measurement based on the difference between the state index of the reference object and the state index of the object under measurement.

[0045] The state of the object OBJ to be measured, as determined in the second determination process, may be whether or not the object OBJ is deteriorated. In this case, the reference object is the same material, product, etc. as the object OBJ to be measured, and is not deteriorated. As a second process, the state determination unit 26 may determine that the object OBJ is not deteriorated if the difference between the state index of the reference object and the state index of the object OBJ to be measured is less than or equal to a threshold, and determine that the object OBJ is deteriorated if the difference between the state index of the reference object and the state index of the object OBJ to be measured is greater than the threshold.

[0046] The state determination unit 26 presents the determination result to the user. The state determination unit 26 may also present the determination result to the user visually, for example, by displaying the determination result on a display unit (not shown).

[0047] The above describes the basic configuration of the state determination system 1. Next, we will explain its operation.

[0048] Relationship information representing the relationship between state indices and states for various states, i.e., reference objects of different degrees of deterioration, is stored in the storage unit 28 in advance. The irradiation unit 10 irradiates the object under test OBJ with electromagnetic waves W1, and the detection unit 12 detects electromagnetic waves W2 that have been transmitted through or reflected by the object under test OBJ. The state determination device 14 generates a spectral spectrum from the electromagnetic waves W2 and generates a state index based on the spectral spectrum. The state determination device 14 refers to the relationship information stored in the storage unit 28 and determines the state corresponding to the state index.

[0049] According to this embodiment, the influence of peaks originating from crystal photon vibrations can be avoided or reduced, thereby enabling more accurate determination of the state of the object OBJ under measurement.

[0050] The present disclosure has been described above based on embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of their components and processing processes, and that such modifications are also within the scope of the present disclosure. Such modifications will be described below.

[0051] (Variation 1) When the same electromagnetic wave W1 is irradiated onto a reference object and the object under test (OBJ), even if the reference object and the object under test (OBJ) are made of the same material and are in the same state of degradation, the absorbance will be higher if the object under test (OBJ) is thicker than the reference object, and lower if the object under test (OBJ) is thinner than the reference object. Therefore, if the thickness of the reference object and the object under test (OBJ) are different, even if everything else is exactly the same, the state indices of the reference object and the object under test (OBJ) will be different, and it may be determined that they are in different states. For this reason, in order to determine the state of the object under test (OJB) with even greater accuracy, the difference in thickness between the reference object and the object under test (OBJ) may be taken into consideration.

[0052] In detail, before generating the state index of the object OBJ under test, the state index generation unit 24 generates the spectral spectrum (I) of the object OBJ under test. OBJ A correction is applied to the OBJ of the object being measured, taking into account the difference in thickness between the reference object and the object being measured. The spectral spectrum (I') of the object being measured after the correction is applied is then calculated. OBJ ) is expressed by the following equation (1).

number

[0053] Thickness of the reference object x ref and the thickness x of the object OBJ being measured OBJ This can be measured using a known measuring instrument such as a micrometer.

[0054] According to this modified example, the state of the object OJB can be determined with high accuracy even when the thickness of the reference object and the object OJB of the object being measured are different.

[0055] (Modification 2) The embodiments and the above-described modifications describe a case where the state of the object OBJ under measurement is a state related to deterioration, but the invention is not limited to this.

[0056] For example, the second determination process may be a process that determines whether the state of the object under test, more specifically whether the state of the object under test differs from the state of the reference object, based on the difference between the state index of the reference object and the state index of the object under test OBJ. For example, the state of the object under test OBJ may be whether or not the object under test OBJ is defective. For example, if the object under test OBJ is defective when its molecular weight is low, and the slope of the spectral distribution tends to increase as the molecular weight of the object under test OBJ decreases, then it can be determined whether or not it is defective, similar to how it is determined when it has deteriorated.

[0057] Any combination of the embodiments and modifications described above is also useful as an embodiment of this disclosure. The new embodiments resulting from such combinations possess the combined effects of the respective embodiments and modifications. [Explanation of symbols]

[0058] 1 state determination system, 10 irradiation unit, 12 detection unit, 14 state determination device, 24 state index generation unit, 26 state determination unit, 28 storage unit.

Claims

1. A state index generation unit generates a state index for determining the state of an object to be measured based on a spectral spectrum obtained from electromagnetic waves transmitted through or reflected by an object to be measured, after the object to be measured is irradiated with electromagnetic waves. A state determination unit that determines the state of the object to be measured based on the state index of the object to be measured, Equipped with, The state index generation unit generates the state index using the intensity of the spectral spectrum in a frequency range unaffected by peaks, generates the state index of the object to be measured after applying a correction to the spectral spectrum to reduce the effect of peaks, or generates the state index based on the intensity of the spectral spectrum at multiple frequencies extracted at frequency intervals of 1 / 2 or less of the peak width. State determination device.

2. The state determination device according to claim 1, wherein the state determination unit determines the state of the object to be measured based on the difference between the state index of the object to be measured and the state index of a reference object.

3. The state determination device according to claim 1, wherein the state determination unit determines the state of the object to be measured based on relational information representing the relationship between the state index of the reference object and the state of the reference object.

4. The state index is the intensity of the spectral spectrum at a specific frequency, the first derivative of the spectral spectrum at a specific frequency, the amount of change in the spectral spectrum within a specific frequency range, the average value of the intensity of the spectral spectrum within a specific frequency range, and the average value of the first derivative of the spectral spectrum within a specific frequency range. The state determination device according to claim 1.

5. The state index generation unit applies a correction to the spectral spectrum that takes into account the difference in thickness between the object to be measured and the reference object before generating the state index of the object to be measured. A state determination device according to claim 2 or 3.

6. The state determination device according to claim 1, wherein the electromagnetic waves irradiated onto the object to be measured are electromagnetic waves in the frequency range of 1 THz to 2 THz.

7. An irradiation unit that irradiates the object to be measured with electromagnetic waves, A detection unit for detecting electromagnetic waves that have passed through or been reflected by the object to be measured, A state determination device according to claim 1, A state determination system equipped with the following features.

8. A determination method for determining the state of an object to be measured, The process involves irradiating the object to be measured with electromagnetic waves, The detection of electromagnetic waves that have passed through or been reflected by the object to be measured, To generate a state index for determining the state of the object being measured based on the spectral spectrum obtained from the detected electromagnetic waves, Determining the state of the object to be measured based on the state index of the object to be measured, Equipped with, In generating the above, the state index is generated using the intensity of the spectral spectrum in a frequency range unaffected by the peak; the state index of the object being measured is generated after applying a correction to the spectral spectrum to reduce the effect of the peak; or the state index is generated based on the intensity of the spectral spectrum at multiple frequencies extracted at frequency intervals of 1 / 2 or less of the peak width. Judgment method.

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