Identification device, identification method, and article manufacturing method

Abstract

To provide an identification device which achieves both of high S / N and high throughput.SOLUTION: An identification device for identifying a type of an object comprises: an illumination unit which illuminates the object; a sensor which measures reflection light from the illuminated object; and a processing unit which identifies the type of the object on the basis of the measurement result by the sensor. The illumination unit comprises: a scan part which scans illumination light that illuminates the object; and a control part which controls the scan part. The control part controls the scan part on the basis of the position of the object such that the illumination light tracks the moving object and the position of the illumination light on the surface of the object is changed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides identification Device, identification The present invention relates to a method for manufacturing a method and an article. [Background technology]

[0002] Traditionally, resin molded parts have been widely used for structural and exterior components of automobiles and electrical appliances due to their ease of mass production and component costs. In recent years, the industrial sector has been forced to become more environmentally conscious, and these resin molded parts are also being recycled and reused. In conventional recycling, scrap automobiles and discarded home appliances are subjected to various recycling processes to recover iron, aluminum, and other materials, and then crushed to sizes of approximately 10 to 100 mm, and the resulting residue, including various types of plastics, is recovered. Ultimately, the waste is often reused through thermal recycling, where it is burned as fuel.

[0003] Efforts are also being made to recycle these plastic residues horizontally, using them again as materials for resin molded parts, and resin identification devices have been developed that can identify and separate specific types of plastic from residues containing a variety of plastics.

[0004] As a measurement method for identifying the type of resin in a non-contact manner by irradiating light, the following technique for identifying the type of resin by utilizing Raman scattering has been disclosed.

[0005] Patent Document 1 discloses a resin identification device that can obtain a strong Raman scattering signal without damaging or deteriorating the resin by translating the illumination light when measuring resin flowing on a belt conveyor using Raman spectroscopy. During irradiation with excitation laser light, the light collection optical system is translated relative to the upper surface of the mounting table over a range equal to or greater than the spot diameter of the excitation laser light on the object, preferably over a range equal to or greater than two to three times the spot diameter. This prevents the excitation laser light from being concentrated on one point on the object, resulting in a resin identification device that does not damage or degrade the object. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-36971 A Summary of the Invention [Problem to be solved by the invention]

[0007] In Patent Document 1, it is possible to identify resin types using Raman measurement without denaturing the resin even when irradiated with a high-power laser. Generally, Raman measurement requires measuring very weak signals, and a high-power laser light source is required to configure an identification device. However, when considering an inexpensive LD that can be installed in the device as a light source, the LD output is limited, so the S / N ratio must be improved. To obtain a Raman signal with a high S / N ratio, for example, the belt speed can be slowed down, the exposure time of the sensor can be extended, and signal strength can be increased, or noise can be reduced by performing repeated averaging and measurement.

[0008] On the other hand, because large amounts of resin residue are generated in the recycling process at a rate of 1 t / h or 2 t / h, it is necessary to increase the throughput of the identification process, and it is desirable to increase the speed of the belt conveyor.If the speed of the belt conveyor is increased in order to meet the requirement for throughput, the time that the sample is present directly under the illumination light will be shorter, making it impossible to ensure the exposure time of the spectrometer for Raman measurement, or the number of repeated averages cannot be ensured, making it difficult to ensure the S / N ratio.

[0009] As described above, there has been a problem in that it is difficult to achieve both a high S / N ratio and high throughput when sorting resins.

[0010] Therefore, an object of the present invention is to provide an identification device that achieves both a high S / N ratio and high throughput. [Means for solving the problem]

[0011] An identification device according to one aspect of the present invention for solving the above problems includes: Moving An identification device for identifying a type of object, comprising: a scanning unit that scans an illumination light that illuminates the object; a control unit that controls the scanning unit; and a light receiving unit that receives light from the object illuminated by the illumination light, wherein the control unit Moving The scanning unit is controlled to illuminate the object based on information about the object's properties. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an identification device that achieves both a high S / N ratio and high throughput. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 illustrates a sorting system. [Figure 2] FIG. 2 is a diagram showing details of a measuring unit 30. [Figure 3] FIG. 10 is a diagram showing how illumination light is scanned by a galvanometer scanner. [Figure 4] 1 is a diagram showing how illumination light is scanned in a scanning area 400. FIG. [Figure 5] FIG. 10 is a diagram showing a scanning trajectory when measuring multiple samples within a scanning region. [Figure 6] FIG. 10 is a diagram showing how a sample outside the scanning area is measured. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0015] 1 is a diagram showing the configuration of a sorting system. The sorting system of this embodiment has a belt conveyor 1 (moving unit) that moves samples (objects), performs an identification process to identify the type of sample transported by the belt conveyor 1, and sorts the samples according to the identification results.

[0016] Samples 10 and 11 are metal pieces mainly containing metal, ceramic pieces mainly containing crystalline metal oxide, glass pieces containing amorphous metal oxide, resin pieces mainly containing resin, etc. In many cases, Samples 10 and 11 are industrial waste such as electrical appliance waste and automobiles that have been crushed into flat pieces of about 10 to 100 mm in size after undergoing a crushing process as a pre-process in recycling.

[0017] Here, the term "resin" in this specification refers to organic polymers in general, including thermoplastic resins (plastics), thermosetting resins, rubber, elastomers, cellulose, paper, and the like.

[0018] Samples 10 and 11 may contain fillers such as glass or fiber, and various additives such as flame retardants and plasticizers.

[0019] The sorting system according to this embodiment not only identifies the type of resin that constitutes the resin pieces, i.e., the material type (material quality, color, etc.) of the resin pieces, but also identifies the presence or absence and type of these additives.

[0020] In the sorting device of this embodiment, samples to be sorted are fed onto a belt conveyor 1 by a fixed quantity dispensing device or a vibrating feeder (not shown), and the samples flow along the belt conveyor 1. Arranged on the belt conveyor 1 from the upstream side of the flow of the belt conveyor are a recognition unit 2 (measurement unit), a measurement unit 3, and a sorting unit 162, and the sample 10 passes below the recognition unit 2 and the measurement unit 3, and then is projected from the belt conveyor 1 and passes in front of the sorting unit 162.

[0021] The recognition unit 2 performs image processing of a two-dimensional image including a sample, which is acquired by, for example, an area camera capable of acquiring two-dimensional images all at once or a line camera capable of reconstructing two-dimensional images. For example, the recognition unit 2 calculates the coordinates of the position where the sample 10 exists at time t0 as p1(x1, y1) from the information on the shape and size of the sample as a result of the image processing.

[0022] 3, the measurement unit 3 has galvanometer scanners 41 and 42 (scanning units) that scan illumination light 50, and an optical spectroscopic unit 30 that measures Raman scattered light (reflected light) from the sample. By controlling the scanning units to tilt the chief ray of illumination light 50, the illumination light is tilted as shown at 50a or 50b with respect to the measurement unit 3, making it possible to move the illumination light (measurement point).

[0023] As shown in FIG. 2, the optical spectroscopic unit 30 has a light source 301 and a lens 302 (illumination unit). The optical spectroscopic unit 30 irradiates a mirror configured in a galvanometer scanner with laser light from a light source 301 as illumination light 50 via lenses 302 and 304. A dichroic mirror 303 is disposed between the lenses 302 and 304, and is configured to transmit light of the wavelength λ of the light source 301.

[0024] The processing unit 140 has a control unit that controls the galvanometer scanners. The processing unit 140 calculates the position coordinate p1 (x1, y1 + V(t1-t0)) of the moving sample at time t1 from the speed V of the belt conveyor 1, which has been adjusted or measured in advance, and the time t0 when the sample is recognized by the recognition unit 2. The processing unit 140 then outputs a control command to the galvanometer scanners so that the illumination light 50 illuminates the sample 10 when the sample 10 reaches a scanning region 400 where the galvanometer scanners 41 and 42 can scan with the illumination light 50. The processing unit 140 then controls the galvanometer scanners so that the illumination light 50 follows the moving sample 10. By using the two scanners, the galvanometer scanners 41 and 42, the illumination light can be scanned in the y-axis direction, which is the moving direction of the belt conveyor 1 (sample), and in the x-axis direction, which is perpendicular to the y-axis.

[0025] Specifically, as shown in Figure 4, when the sample 10 reaches the upstream boundary of the movement of the belt conveyor 1 in the scanning area 400 (10a), the illumination light is scanned at the position of the illumination light 50a, and measurement begins. Raman measurement is performed by illuminating the sample 10 so that it traces a trajectory 60 on the sample as it moves at a speed V in accordance with the movement of the belt conveyor 1. Then, measurement is completed when the sample 10 reaches the downstream boundary of the belt conveyor 1 in the scanning area 400 (10b). Here, the trajectory from the illumination light 50a to 50b indicates the average position of the scanning illumination light 50.

[0026] The size of the scanning area 400 in the belt movement direction is defined as B. The position of the illumination light 50 changes in the same direction as the belt movement direction, and the illumination light illuminates the sample 10 for a time T=B / V so that it follows the sample 10, and illuminates without remaining at a single point on the surface of the sample 10 during illumination.

[0027] Therefore, the energy of the illumination light is not concentrated on one point of the sample, and Raman measurement can be performed without denaturing the resin. Moreover, because the speed of the belt conveyor can be increased, even if a large number of samples are flowed on the belt conveyor to increase the identification throughput, they can be arranged in a spatially separated state.

[0028] In the case of a conventional method in which the illumination light 50 is not scanned, the size of the sample 10 in the belt movement direction is a, and the illumination light 50 is irradiated for a time period of t=a / V.

[0029] As an example, we will describe the case where the speed of the belt conveyor is 1 m / s, the size of sample 10 is 10 mm, which is assumed to be the smallest size of a sample in the recycling process, and the scan area of ​​B is set to 200 mm.

[0030] With conventional methods that use a fixed illumination light, the time t during which illumination light can be applied is 10 ms, whereas if illumination light 50 is scanned and measured while tracking the sample, there is approximately 200 ms to measure. Therefore, for black resins with a low amount of reflected light, the S / N of weak Raman signals can be improved by extending the exposure time or averaging 20 sets of data acquired with a 10 ms exposure time.

[0031] On the other hand, in this embodiment, the illumination light 50 traces a zigzag trajectory like trajectory 60 so that the illumination light does not stay in one place while measuring the sample 10. Therefore, the energy of the illumination light is dispersed over a wide area of ​​the sample 10, and the resin is not denatured during the measurement.

[0032] In the optical spectroscopic section 30, as described above, the illumination light 50 is reflected by the mirror sections 41m and 42m of the galvano scanner 41 and the galvano scanner 42, and then irradiated onto the sample. After being reflected by the sample, the Raman scattered light is isotropically reflected and then reflected again by mirrors 41m and 42m of the galvanometer scanner, returning to the optical spectroscopic unit 30. The Raman scattered light undergoes a Raman shift corresponding to the substance of the sample material. Therefore, it is then reflected by a dichroic mirror 303, and only the Raman-scattered components are transmitted by a bandpass filter 305, which acts as an excitation light cut filter, before being dispersed by a spectroscopic element 306 (spectroscopic unit). The light beam dispersed by the spectroscopic element 306 is diffracted at different diffraction angles for each wavelength, and the diffracted light is refocused by a lens 307, and the Raman-shifted light for each wavelength is received by a light-receiving element configured in a sensor array 308. The signal output from the light-receiving element is sent to the processing unit 140 as a characteristic signal corresponding to the substance of the sample. For example, the signal is compared with a waveform specific to the sample obtained by measuring a sample of a known material in advance to identify the material and the type of sample.

[0033] Signals (measurement results) from the sensor array 308 are transmitted to the processing unit 140 at, for example, 300 fps. Measurement begins when the sample 10 reaches the interface on the upstream side of the belt movement in the scanning area 400 (10a), and the processing unit 140 extracts signals corresponding to the measurement from the group of signals transmitted from the sensor array 308 at 300 fps to identify the material. The method for extracting the corresponding signals may be determined, for example, based on the time when the operation command was issued.

[0034] If the processing unit 140 identifies the type of sample and determines that the sample 10 is a material to be sorted, an open signal is sent to the sorting unit 162 via the sorting controller 161 at time t2, when the sample 10 passes through the sorting unit 162. Air is then ejected from a portion of the sorting unit 162 that is located at a position corresponding to the coordinate x1 of the sample 10 measured by the recognition unit 2, and the sample 10 is blown away by the air and collected in the collection box 72. If the sample 10 is not a material to be sorted, the sample 10 is projected from the belt conveyor 1 at a speed V and falls, and is collected in the collection box 71.

[0035] After completing the measurement of sample 10, measurement unit 3 next measures sample 11, and then continues to measure samples (not shown) that flow in one after another. Measurement unit 3 moves to the starting point for measuring sample 11 by rotating galvanometer scanners 41 and 42 to change the tilt angle of illumination light 50. Because the galvanometer scanners can scan the illumination light at high speed, the movement time until the next resin is measured is short, and samples that flow in one after another can be measured. As a result, Raman measurement with a long measurement time and high S / N ratio is possible, and the large number of samples that can be measured enables high-throughput resin sorting.

[0036] In this embodiment, the recognition unit 2 is described as obtaining a two-dimensional image using an area sensor or a line camera and determining the coordinates of the sample through image processing. However, this is not a limitation, and it is also possible to adopt a method that recognizes an object based on height information, such as a light-section sensor. Furthermore, in this embodiment, a zigzag trajectory is used as the trajectory of the illumination light on the resin so that the illumination light does not stay at a single point on the sample. However, it goes without saying that a similar effect can be achieved by using a circular motion, a spiral motion, or a square motion, as long as the illumination light does not stay at a single point on the resin.

[0037] Furthermore, in the configuration of this embodiment, the recognition unit 2 acquires a two-dimensional image including the sample, and the two-dimensional image contains information about the sample's brightness, i.e., diffuse reflectance. According to considerations by those skilled in the art, the intensity of Raman scattered light is correlated with diffuse reflectance, and the Raman scattered light from a bright, white sample is significantly greater than the Raman scattered light from a dark, low-brightness sample. In other words, the measurement time required to obtain the same S / N ratio is shorter for a bright sample than for a dark sample.

[0038] Based on the above facts, it is effective to set the measurement time for white resins shorter than that for black resins in order to identify samples more efficiently and improve throughput. In this case, as shown in Figure 5, for black resin 10, the illumination light is scanned under scanning conditions that measure along locus 61 that moves all over region 400 from position 10a to position 10b.

[0039] On the other hand, the white resin is scanned with illumination light under scanning conditions that shorten the measurement time, for example, by one-third, compared to the black resin. For example, the trajectory of illumination light 50 is scanned along a stepped trajectory 62. This allows multiple horizontally arranged, high-brightness samples 12, 13, and 14 to be measured while moving from position 12a to 12b, from position 13a to 13b, and from position 14a to 14b. Of course, in this case, trajectories 61 and 62 also indicate the average position of the scanning illumination light 50, and it goes without saying that the average position of illumination light 50 simultaneously traces trajectory 60 on the resin while moving along each trajectory. In this way, the processing unit has a control unit that controls the scanning unit to change the scanning conditions of the illumination light based on information about the object.

[0040] The flowing samples vary in size and color. As already mentioned, the higher the brightness of a sample, the stronger the Raman scattering intensity, and the lower the brightness, the weaker the Raman scattering light. In other words, the higher the brightness, the higher the reliability of identification to identify the resin type, and the lower the brightness, the lower the reliability of identification to identify the resin type. It goes without saying that the higher the purity of the desired type of resin being recovered, the more useful it is, but it is preferable to recover more resins with higher brightness, as this increases the reliability of identification on average and, as a result, also increases the purity of the desired resin recovered.

[0041] On the other hand, since the samples flowing over area 400 are actually randomly arranged on belt conveyor 1, there is a certain probability that the density of samples present will be high, and it is assumed that there will not be enough time for the scanning of illumination light 50 to measure all of the resin groups with high density in order. In this case, processing unit 140 can simply issue a command to galvano scanners 41 and 42 to skip measuring one of the samples. In other words, when multiple objects are present within the scannable range of illumination light, processing unit 140 determines the object to be measured based on object information.

[0042] At this time, the purity of the finally collected samples can be improved by prioritizing measurement of samples with higher brightness based on the brightness information of each sample in the image obtained by the recognition unit 2. Furthermore, it is also effective to increase the amount of resin finally collected by prioritizing measurement of larger samples based on the shape information of the samples obtained by the recognition unit 2.

[0043] In this embodiment, the speed of the belt conveyor 1 is assumed to be a pre-measured or adjusted speed V, and the operation of tracking the illumination light in the measurement unit 3 and the sorting operation in the sorting unit 162 are configured to issue commands based on time. However, for example, a laser Doppler velocimeter or an image correlation displacement meter that directly measures the belt speed can be installed near the recognition unit 2 or measurement unit 3, and measurements of the belt movement from these measuring devices can be input to the processing unit 140. This allows for issuing operation commands to the galvanometer scanners 41 and 42 based on the measured belt movement, enabling more accurate tracking of the illumination light and sorting operation in the sorting unit 162, which is also effective in increasing the recovery amount. In this case, the signal when the sample is illuminated can be extracted from the signals transmitted from the sensor array 308 using the measured belt movement at the time each signal is generated. This allows for more accurate extraction of the signal when the illumination light 50 is staying on the resin.

[0044] Regarding signal extraction, it is also effective to measure a sample (specimen) exhibiting known specific characteristics (features) not anticipated during normal measurement, such as a sample with high reflectivity that saturates, immediately before moving to the measurement start point or before a specified time. For example, as shown in Figure 6, a fluorescent sample 20 with high fluorescence and whose measurement value saturates on the sensor array 308 is placed outside the scanning area 400 and in a position measurable by the measurement unit 3. Then, just before scanning the sample 10 to position 10a where the sample 10 reaches the interface on the upstream side of the belt movement in the scanning area 400, or before a specified time, the illumination light 50 is turned to 50c to measure the fluorescent sample 20. This simplifies the extraction of measurement data in the downstream processing unit 140. The processing unit 140 simply extracts and processes the data immediately after the data where the level of each element reaches its maximum value or the data after a specified number of data points from the data continuously transferred from the sensor array 308 as data to be used for sample material determination.

[0045] Samples that exhibit characteristic data are not limited to these, and can also be light traps that reflect very little light, alloy resins that simultaneously exhibit the characteristics of multiple resins, or any sample that exhibits known characteristics that are not expected in normal measurements.

[0046] As explained above, based on the resin information recognized by the recognition unit 2, the scanning unit, such as a galvanometer scanner, changes the angle of the chief ray of the illumination light so that the average position follows the direction of belt movement. Furthermore, by scanning the illumination light so that it does not remain at the same position on the resin during measurement, Raman spectroscopy is performed for point measurements while tracking the sample even at high belt speeds, making it possible to identify resins by Raman spectroscopy with a high S / N ratio and high throughput.

Claims

1. An identification device for identifying the type of a moving object, comprising: a scanning unit that scans the object with illumination light; a control unit that controls the scanning unit; a light receiving unit that receives light from the object illuminated by the illumination light, The control unit controls the scanning unit to illuminate the object based on information about characteristics of the moving object.

2. 2. The identification device according to claim 1, wherein the control unit controls the scanning unit so as to illuminate the object while moving an irradiation position of the illumination light on the surface of the object.

3. 2. The identification device according to claim 1, wherein the control unit controls the scanning unit so that the illumination light does not stay at one point on the surface of the object.

4. 2. The identification device according to claim 1, wherein the scanning unit scans the illumination light in a direction perpendicular to the moving direction of the object while scanning the illumination light in the moving direction of the object.

5. 2. The identification device according to claim 1, wherein the control unit controls the scanning unit to change a scanning condition of the illumination light based on information relating to characteristics of the moving object.

6. 2. The identification device according to claim 1, wherein when a plurality of objects are present within a scannable range of the illumination light, the control unit determines the object to be identified based on information regarding the characteristics of the moving object.

7. The moving object includes a first object and a second object; 2. The identification device according to claim 1, wherein the control unit controls the scanning unit so as to differentiate an illumination time for illuminating the first object from an illumination time for illuminating the second object having characteristics different from those of the first object, based on information regarding characteristics of the moving object.

8. 2. The identification device according to claim 1, wherein the information about the property of the moving object is the measured brightness of the object.

9. The identification device according to claim 1 , wherein the control unit changes the time for illuminating the object based on the brightness of the object.

10. 2. The identification device according to claim 1, wherein when a first object having a first brightness and a second object having a second brightness higher than the first brightness are illuminated while being scanned by the scanning unit, the control unit controls the scanning unit so that the illumination time of the first object is longer than the illumination time of the second object.

11. 2. The identification device according to claim 1, wherein the information relating to the characteristics of the moving object is information relating to at least one of the shape and size of the object.

12. The identification device according to claim 1 , wherein the control unit controls the scanning unit based on the information and information relating to the position of the moving object.

13. 2. The identification device according to claim 1, wherein the control unit controls the scanning unit based on the information and information relating to at least one of a conveying direction and a conveying speed of the moving object.

14. 2. The identification device according to claim 1, further comprising a recognition unit that acquires information about characteristics of the moving object.

15. 2. The identification device according to claim 1, further comprising a processing unit that identifies the type of the object based on the result of light reception by the light receiving unit.

16. 16. The identification device according to claim 15, wherein the processing unit identifies the type of the object using data obtained by receiving light from a sample illuminated in advance by the illumination light using the light receiving unit.

17. 2. The identification device according to claim 1, further comprising a measurement unit for measuring the position of the moving object.

18. 2. The identification device according to claim 1, further comprising a measurement unit for measuring at least one of the position and the velocity of the moving object.

19. 2. The identification device according to claim 1, further comprising a spectroscopic unit that separates light from the object illuminated by the illumination light.

20. 2. The identification device according to claim 1, wherein the scanning unit is a galvanometer scanner.

21. the object is a resin, The identification device according to claim 15 , wherein the processing unit identifies the type of the resin.

22. 2. The identification device according to claim 1, further comprising a moving unit that moves the object.

23. 2. The identification device according to claim 1, wherein the light receiving section receives reflected light from the object illuminated by the illumination light.

24. 2. The identification device according to claim 1, wherein the light receiving section receives Raman scattered light from the object illuminated by the illumination light.

25. 2. The identification device according to claim 1, wherein the light receiving section receives scattered light from the object illuminated by the illumination light.

26. An identification device according to any one of claims 1 to 25; a sorting unit that sorts objects based on the results of identification by the identification device.

27. A method for identifying a type of moving object, comprising: a scanning step of scanning illumination light that illuminates the object; a light receiving step of receiving light from the object illuminated by the illumination light, The method for identifying an object, wherein the scanning step scans the illumination light so as to illuminate the object based on information about characteristics of the moving object.

28. an identification step of identifying the object using the identification method of claim 27; a sorting step of sorting the object based on the identification result of the identification step.

29. 27. A method for manufacturing an article, comprising: a sorting step of sorting objects using the sorting device according to claim 26; and a processing step of manufacturing an article by processing the objects sorted by the sorting step.

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