JP5636870B2 - Online nondestructive spectrometer - Google Patents

Description

The present invention performs the measurement of the internal condition of the object to be measured coming sequentially conveyed by a conveying device online at and non-destructive, it relates to on-line non-destructive spectrometer.

As a spectroscopic analyzer that optically and non-destructively measures the internal properties of objects to be measured such as fruits and vegetables, the transmission light of the light irradiated from the light source to the object to be measured is dispersed with a diffraction grating, and the spectrum of the required wavelength is lined up. There are some which measure by a sensor, perform calculation processing and waveform analysis by a signal processing and control device, and perform calculation processing using a calibration curve (for example, see Patent Document 1 and Patent Document 2).
In such a non-destructive spectroscopic analysis apparatus, Patent Document 2 discloses an on-line non-destructive spectroscopic analysis apparatus that measures on-line the internal properties of objects to be measured having different sizes (optical path lengths) that are sequentially transported by a transport device (conveyor). A single optical axis projector (light source) and a light receiving sensor as the size measuring device of the object to be measured are located at the same height as the center of the light receiving area of the transmission spectrophotometer on both sides upstream of the transport path. The size of the object to be measured is measured from the light blocking time by the object to be measured that is sequentially conveyed, and the measurement start timing and the line sensor for accumulating the photo charge with respect to the transmission spectrophotometer Giving accumulation time.

JP-A-6-213804 Japanese Unexamined Patent Publication No. 7-229840

  However, in the method of measuring the size (size) of the object to be measured from the light blocking time as in Patent Document 2 (hereinafter referred to as “light blocking method”), for example, a part necessary for measurement such as an onion ( In the following, in addition to the scale leaves, which are “measurement-required parts”, parts that are not necessary for measurement of the floating protective leaves (skin), neck (buds), roots, etc. (hereinafter referred to as “measurement-unnecessary parts”) )) When a certain object to be measured is transported in an uneven posture, the error in size measurement of the object to be measured becomes large, and the accumulation start and accumulation end timings calculated from the conveyance speed are shifted. Even if there is no saturation in the data, there is a problem that the spectrum accuracy of the measurement unnecessary portion and the measurement required portion is added and the measurement accuracy deteriorates.

Further, in an on-line type nondestructive spectroscopic measurement apparatus, the transmission spectrophotometer needs to measure faint light (about 10 ⁻⁶ to 10 ⁻⁷ ). In order to obtain a range, it is driven by a charge accumulation method, and the accumulation time is expanded or contracted depending on the object to be measured and the measurement method.
Therefore, when there is a portion having a high transmitted light intensity of light such as a root of hair or an epidermis in the object to be measured, there is a problem that measurement is impossible due to saturation in spectrum data.
In addition, when there is strong transmitted light from the object under measurement for a moment during measurement, the light receiving sensor and the amplifier circuit are saturated, and it takes time to discharge the photodiode charge for the next measurement. When the measurement object is conveyed at a high speed, there is a problem in that these measurement objects cannot be continuously measured.

Furthermore, in the light blocking method, an object with a measurement-unnecessary part cannot be accurately measured for the measurement-required part of the object to be measured. Although the measurement accumulation start timing is delayed and the accumulation end timing is set earlier to give a margin, in such measurement, the photocharge accumulation time of the light receiving element group is shortened. There is a problem that the measurement data does not include information near both ends of the measurement-required part.
Furthermore, depending on the type of the object to be measured, it is necessary to change the height of the light projecting / receiving unit of the transmission spectrophotometer. It is necessary to mechanically connect an upstream size measuring and measuring unit to the transmitting and receiving unit of the transmission spectrophotometer. Especially for long objects such as burdock or radish, the size measuring instrument and the transmission type The distance of the spectrophotometer becomes longer, and the transmission / reception unit of the transmission spectrophotometer and the light emitter / receiver of the size measuring instrument are moved up and down in a stable and highly accurate manner in response to a command from a computer of the transmission spectrophotometer. Therefore, there is a problem that the structure of the drive system and the mechanical system becomes complicated and large.
In addition, the configuration in which the camera is installed on the upstream side of the transmission spectrophotometer (see, for example, FIGS. 1 and 2) is not realistic because a mechanism for moving up and down in parallel across the camera is required.

It is also conceivable to take an image of the object to be measured by the camera, perform size measurement and shape determination of the object to be measured, and calculate the accumulation start timing, but in such a system, for example, attachment of large leaves, large epidermis, Agricultural crops with long shoots are objects to be measured, and when such objects to be measured are transported in an uneven posture, the position of the measurement required part is out of the image area of the camera, making analysis impossible. There is a problem.
Furthermore, for example, depending on the object to be measured, there is a part where the measurement required part is hidden by a leaf or the like, and a bulge by the epidermis keeps the shape of the onion like an onion, and the reflected light from the object to be measured It is impossible to determine the shape by camera imaging.
Furthermore, for various types of objects to be measured, or for the same type, there are large differences in size, and the objects to be measured include complex shapes of leaves, roots, buds, etc., and measurement unnecessary parts such as packaging containers and films On the other hand, the shape determination in the camera image analysis using general reflected light is inaccurate because the accuracy of calculation of the measurement required part is poor and the determination in the camera image analysis is not practical. It is.

  It is also conceivable to use a two-dimensional image sensor or a line sensor for shape determination to image transmitted light with strong light. For example, it may pass through a measurement-unnecessary site such as an epidermis or a root of hair on which onions overlap. As a result, intense light is irradiated to the photodiode of the two-dimensional image sensor or line sensor in the unshielded area around the object to be transported and the gap between the objects to be transported next. Because the photodiode junction capacitance is finite, the signal charge exceeding the saturation charge cannot be accumulated and overflows outside, and the overflowing charge causes a blooming phenomenon that affects the adjacent photodiode and video line. Even if an image sensor or line sensor with general anti-blooming measures is used, the above-mentioned strong It does not deserve to practical use under the conditions of light.

Therefore, in view of the above-described situation, the present invention intends to solve the problem even when measuring an internal property while transporting an object to be measured including a measurement-unnecessary portion in an uneven posture. On-line non-destructive that can minimize errors in size measurement of objects, has a wide measurement range, high measurement accuracy, and can easily respond to changes in the height of the transmission / reception unit of a transmission spectrophotometer It is in providing a spectroscopic analyzer.

On-Line nondestructive spectrometer according to the present invention, the transmission for the problem solving, orientation come sequentially conveyed in a irregular state by conveying device, the measurement of the internal condition of the object to be measured including the measurement unnecessary site A non-destructive on-line spectrophotometer using a spectrophotometer, wherein the carrier device outputs a clock signal synchronized with the carrier, and two-dimensionally measures the transmitted light intensity distribution of the object to be measured. For this purpose, the transmission type light gate section includes a light emitting element group installed upstream of the transmission type spectrophotometer and a light receiving element group for receiving the light emitted by the light emitting element group, and the transmission type light gate unit. The gate portion detects the first measurement unnecessary portion of the measured object whose transmitted light intensity is higher than a predetermined threshold, and transmits the second measurement unnecessary portion of the measured object that cannot be detected only by the transmitted light intensity. Detecting by intensity and shape determination, calculating the size and effective measurement area of the measurement target part of the object to be measured, excluding the first measurement unnecessary part and the second measurement unnecessary part, and for the transmission spectrophotometer The integrated transmitted light intensity signal for controlling the saturation of the spectrum obtained by integrating the transmitted light intensity of the pixels in the effective accumulation region, and the accumulation start point and accumulation time synchronized with the clock signal are output.

  According to such a configuration, the measurement unnecessary part of the object to be measured can be removed by the transmission type optical gate part, and the measurement unnecessary part size and effective measurement of the object to be measured can be removed in this way. Since the area is calculated, the error in measuring the size of the object to be measured can be made extremely small even when the object to be measured that has a measurement unnecessary part in addition to the part to be measured is transported in an uneven posture. Of the accumulation start and accumulation end timing calculated from the conveyance speed of the object to be measured conveyed by the conveyance device (measurement start timing of the transmission spectrophotometer and accumulation time for the line sensor to accumulate the photocharge). Since the deviation can be suppressed, the measurement accuracy is increased.

In addition, since the transmission light gate unit outputs an integrated transmitted light intensity signal for controlling the saturation of the spectrum to the transmission spectrophotometer, the spectrophotometer using this integrated transmitted light intensity signal is output. It is possible to prevent the spectral data from being saturated by controlling the optical aperture.
Therefore, it is possible to measure with the optimal amount of light without saturation, and to obtain a high dynamic range comprehensively by using a light source with strong illuminance in the transmission spectrophotometer, so that the measurement accuracy is increased. As well as a wide measurement range.

Furthermore, in the process of integrating transmitted light within the effective accumulation area, saturation check by strong light is performed, and the transmission spectrophotometer does not measure the object to be measured. If there is a saturated portion in the measurement object, the transmission spectrophotometer can increase the measurement work efficiency by closing the high-speed shutter at that timing and not performing the measurement of the portion.
In addition, even when the height of the light projecting / receiving part of the transmission spectrophotometer is changed, the maximum size of the object to be measured can be obtained by increasing the number of light receiving elements in the height direction in the transmission light gate part. The structure of the drive system and the mechanical system is complicated and large as in the conventional configuration in which the height of the optical axis of the light emitter / receiver of the size measuring instrument is mechanically changed. Therefore, the configuration can be simplified.

Here, the surface abnormality of the object to be measured is formed on the downstream side in the transport direction with respect to the light emitting element group and the light receiving element group of the transmission type optical gate unit and on the upstream side or the downstream side in the transport direction with respect to the transmission type spectrophotometer. A surface imaging device having a camera for imaging the object to be measured and a projector for illuminating the object to be measured, the image center of the object to be measured from the transmission type optical gate unit to the surface imaging device It is preferable to output an imaging start trigger signal and a size synchronized with the clock signal so that the vicinity is located at the center of the image area of the camera.
According to such a configuration, imaging synchronized with the clock signal of the transport device so that the vicinity of the image center of the object to be measured is located in the center of the image area of the camera from the transmission type optical gate unit to the surface imaging device. Since the start trigger signal and the size are output, the position of the measurement-required part does not deviate from the image area of the camera and image analysis is not disabled.
In addition, the overall judgment output, which is a combination of the determination result of the surface abnormality of the measurement object by the image analysis of the surface imaging device and the determination result of the internal property of the measurement object by the transmission spectrophotometer, determines whether the measurement object is good or bad. Since determination and selection can be performed, it is possible to improve the accuracy of determining the quality of the object to be measured.
When the surface imaging device is installed on the downstream side of the transmission spectrophotometer, the distance between the light emitting element group and the light receiving element group of the transmission optical gate section and the transmission spectrophotometer is shortened. The effect of errors due to shaking is reduced, but on the other hand, a buffer memory for the spectral data of the object to be measured on the transport device between the transmission spectrophotometer and the surface imaging device is required, and the timing The algorithm becomes complicated.

As described above, according to the on-line type nondestructive spectroscopic analysis apparatus according to the present invention, even when measuring an internal property while transporting an object to be measured including a measurement unnecessary portion in a state where the posture is not uniform, Error in measuring the size of the object to be measured can be kept small, the measurement range is wide, the measurement accuracy is high, the height of the light transmission / reception part of the transmission spectrophotometer can be easily adjusted, and surface imaging It is possible to effectively perform image analysis when measuring the surface abnormality of the object to be measured using the apparatus, and it is possible to improve the accuracy of determining the quality of the object to be measured.

It is a top view of the on-line type nondestructive spectroscopy analyzer concerning an embodiment of the invention. It is a block diagram which shows the outline | summary of a structure of the same online type | mold nondestructive spectroscopy analyzer. It is the figure which looked at the transmission type optical gate part from the front. It is a block diagram which shows the signal processing by a transmissive | pervious optical gate part. It is a circuit block diagram of a transmissive | pervious optical gate part. It is a figure which shows a timing. It is the schematic which shows the variation of a transmissive | pervious optical gate part, (a) is the example of a structure which arranges a light emitting element group and a light receiving element group so that a focus may be formed in the approximate center, (b) is light projection / reception in an up-down direction The example of a structure to perform is shown.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown in the accompanying drawings, and includes all the embodiments that satisfy the requirements described in the claims. It is a waste. In this specification, the transport direction of the object to be measured (see arrow A in the figure) is the front, the opposite side is the rear, and the left and right are the front.

As shown in FIGS. 1 and 2, on-line non-destructive spectroscopic analyzer according to the embodiment of the present invention, a sequential line measurement of internal condition of the conveyed object to be measured and non-destructive by the transfer device C The light emitted from the light emitting element group P and the light emitting element group P of the transmissive optical gate unit 1 is received from the upstream side to the downstream side in the transport direction (see arrow A in the figure). A light receiving element group R, a surface imaging device 2 and a transmission spectrophotometer 3 are arranged.
In the present embodiment, as an example of an object to be measured, an onion G having a measurement unnecessary portion such as a peeled skin, a leaf, a bud, a root of a beard (thin beard-like root) is mainly shown, and a difference in size is shown. Processed food that has been standardized and packaged, etc., to measure the quality of rot, etc., on or outside of the onion G that is transported at high speed in irregular directions (in an irregular posture) with large epidermis, buds, etc. Unlike, it is very difficult.

  The transmissive optical gate unit 1 projects the projection light L1 from the light emitting element group P, and receives the received light L2 by the light receiving element group R. As will be described later, in each part of the onion G that is the object to be measured. By determining the level of light transmission and the shape determination, the measurement unnecessary part and the measurement unnecessary part are removed, the measurement unnecessary part is removed, the diameter and effective accumulation area of the onion G are calculated, and the transmission spectrophotometer 3 is Accumulated transmitted light intensity signal B for controlling the saturation of the spectrum obtained by integrating the transmitted light intensity of the pixels in the effective accumulation region, and the accumulation start point and accumulation time that are the spectrophotometer measurement timing size T are output, The camera measurement timing and size TC are output to the surface imaging device 2.

Moreover, the surface imaging device 2 measures the surface abnormality of the onion G, the camera 21 that images the onion G from above, the projector 22 that illuminates the onion G, and the reflections installed on the left and right of the conveyance path. Side mirrors 23 and 23, a camera interface 24, and the like.
Further, the transmission spectrophotometer 3 measures the internal properties of the onion G and the like, and includes a light source 37 including a halogen lamp 38 that irradiates the onion G with light of a predetermined wavelength (for example, near infrared light), A light receiver 33 that receives the transmitted light from the onion G, an optical aperture 34 that adjusts the amount of light, and an optical aperture actuator 35 that drives the optical aperture 34 (may be an electro-optical aperture using liquid crystal or the like), light. The optical imaging device 36 for transmitting the light, the spectroscope for spectrally processing the transmitted light from the onion G and the control unit 31, and the calibration curve (discriminant) for evaluating the internal properties of the onion V are used for arithmetic processing and the surface imaging device 2 The spectroscope calculation unit for analyzing the camera image and the camera image analysis unit 32 and the like.
As shown in FIG. 1, the side mirrors 23 and 23 are arranged on the left and right sides, and the light source 37 and the light receiver 33 are also arranged on the left and right sides. However, in FIG. It is arranged in the front-rear direction.

In the transmissive optical gate section 1 shown in FIG. 3, the light emitting element group P is formed by light emitting elements P1, P2,..., P20 arranged in series in the vertical direction, and the light receiving element group R is light emitting elements P1, P2,. , P20, which are respectively opposed to P20, and the pulse-modulated light emitted by the light-emitting elements P1, P2,. The light receiving elements R1, R2,..., R20 facing each other with a narrow directivity angle are respectively irradiated.
The number of light emitting elements P1, P2,... And light receiving elements R1, R2,... Is not limited to 20 as in the example shown in FIG. The light emitting elements P1, P2,... And the light receiving elements R1, R2,.

Here, as the light emitting elements P1, P2,..., For example, light emitting diodes or laser diodes are used. For example, the onion G selects a wavelength band of about 820 nm with little moisture attenuation. It is also possible to select the optimum wavelength for the determination.
In addition, when a strong laser diode is used as the light emitting elements P1, P2,..., The gain of the light receiving elements R1, R2,... Can be reduced, but in this case, the light emitting elements P1, P2,. And the light receiving elements R1, R2,... May be shifted slightly to avoid direct light.

FIG. 4 shows the onion G on the conveying device C in a direction in which the protruding portion of the bud passes through the light receiving surface of the light receiver 33 of the transmission spectrophotometer 3 while synchronizing with the carrier synchronizing clock signal (clock pulse) CL. The transport direction is schematically illustrated, the transport direction is the X axis, the positions of the light emitting element group P and the light receiving element group R of the transmissive optical gate unit 1 are X = 0, and the light receiving element group R (light receiving element R1). ˜Rn) is the Y axis, and the surface height of the conveying device C is Y = 0.
The transmissive optical gate unit 1 outputs the output waveforms S1 to Sn from the X-axis carrier synchronization clock signal CL and the Y-axis light receiving element group R (light receiving elements R1 to Rn) via the analog multiplexer 16 of the one-chip CPU 20 to A. It can be digitized by the / D converters 17 and 18 to obtain a two-dimensional image represented by transmitted light intensity as will be described later.

Next, a circuit configuration example of the transmissive optical gate unit 1 will be described.
As shown in FIG. 5, in order to increase the luminance with a duty ratio of 1/5, the light emitting element driving circuit 9 of the light projecting unit circuit 7 is applied with a light emitting element driving pulse 14 of, for example, 20 μsec at a cycle of 100 μsec. Driving is performed by supplying a current about five times the steady current to the light emitting elements P1, P2,... (See also FIG. 3).
The light pulse-modulated by the pulse drive is incident on the light receiving elements R1, R2,... (See also FIG. 3) of the light receiving unit circuit 8, and becomes an input current of the preamplifier 10 due to the photovoltaic effect. Is converted into a voltage.
The NPN type anti-saturation FET 11 has a drain connected to the input (−) of the preamplifier 10, a source connected to the output side, and an anti-saturation bias voltage V1 applied to the gate.

When the incident light is strong and the negative voltage output of the pre-amplifier 10 lowers the source potential of the anti-saturation FET 11 and approaches the threshold of the gate voltage, the drain and the source of the anti-saturation FET 11 begin to conduct, and the gain of the pre-amplifier 10 Is lowered and clamped at a certain level.
In strong incident light without light being blocked by the device under test (eg, onion G), an appropriate output can be obtained by adjusting the anti-saturation bias voltage V1.

The zero point correction circuit 13 makes the output of the preamplifier 10 zero immediately before the light emitting element driving pulse 14 by the zero point correction pulse 15, and the preamplifier 10 including disturbance light, light receiving elements R1, R2,. The noise having the pulse width equal to or larger than the sum of the zero point correction pulse 15 and the light emitting element driving pulse 14, that is, the noise component having a frequency equal to or lower than that is canceled.
The post-stage amplifier 12 amplifies the output of the preamplifier 10, and the upper limit of the amplification area of the post-stage amplifier 12 is set by the level shift bias voltage V2 with respect to the output level of the preamplifier 10 by direct incident light.

Here, the anti-saturation bias voltage V1, the level shift bias voltage V2, and the light emitting element current control voltage V3 can be made variable by a DC voltage obtained by integrating the PWM-modulated output of the one-chip CPU 20, respectively. Can be set by the command.
Further, the output (S1 to Sn) of the post-stage amplifier 12 is connected to the analog multiplexer 16 of the one-chip CPU 20, and is 12-bit digitally converted by the A / D converters 17 and 18, and is synchronized with the carrier synchronization clock signal CL (X axis). The two-dimensional image represented by the transmitted light intensity (Y axis) is stored in the RAM of the one-chip CPU 20.

Necessary parameters of the transmissive optical gate unit 1 and mutual communication are transmitted and received through the command signal data line 19 shown in FIGS. 2, 4 and 5, and the camera measurement timing size TC, spectrophotometer measurement timing size. T and the signal of the integrated transmitted light intensity signal B are sent to the surface imaging device 2 via the spectroscope and the control unit 31 (see FIGS. 2 and 4).
It should be noted that circuits such as the light projecting circuit 7 and the light receiving circuit 8 of the transmissive optical gate unit 1 may be arranged at positions separated from the light emitting element group P and the light receiving element group R by guiding light through an optical fiber. By doing so, it is possible to configure the transmissive optical gate unit 1 having a light projecting / receiving unit having a high degree of optical freedom according to the object to be measured.

Further, from the two-dimensional image represented by the transmitted light intensity recorded on the RAM of the one-chip CPU 20 in FIGS. 4 and 5, the surface imaging device 2 was obtained by the optical gate image analysis unit 4 by the determination described later. From the total length of the onion G (including the size of the onion sprout) L / 2 at the camera timing size TC from which the skin and the like have been removed, the carrier synchronization clock signal so that the center of the onion G image is in the center of the image area of the camera 21 CL is counted and an imaging start trigger which is a camera measurement timing and size TC is output (see also the timing diagram shown in FIG. 6).
Further, the transmission type spectrophotometer 3 calculates an integrated transmitted light intensity signal B obtained by integrating the transmitted light intensity of the pixels in the effective accumulation region, a spectrophotometer measurement timing size T by the optical gate image analysis unit 4, The carrier synchronization clock signal CL is counted, the data of the transmitted light intensity signal B is output at an early timing in anticipation of the response delay of the optical aperture 34, and then the spectrophotometer measurement timing size T is set to the transmission spectrophotometer 3 And the accumulation is started from the moment when it sufficiently reaches the light receiving surface of the light receiver 33 of the transmission spectrophotometer 3, and the time is converted from the length (size) LN necessary to measure the onion G to obtain the accumulation time (see FIG. (See also timing diagram 6).

  Here, in the case of strong transmitted light intensity, optical aperture is performed by the optical aperture 34 so that the spectral data is not saturated, but when the optical aperture 34 is not equipped, depending on the object to be measured, the accumulation time is shortened. The amount of accumulated charge in the light receiving sensor of the spectroscope can be reduced to the spectral data by increasing the number of divided measurements, increasing the pause time during the divided measurement (discharge time of the charge accumulation sensor), etc. Saturation can be avoided.

  Simultaneously stored in the RAM of the one-chip CPU 20, the two-dimensional transmitted light intensity data (two-dimensional image data represented by transmitted light intensity) of the onion G is sent to the spectroscope and control unit 31 through the command signal data line 19. The spectroscope calculation unit / camera image analysis unit 32 sets a part of the parameters of the spectral analysis and the camera image analysis. The determination result of the surface abnormality of the onion G by the image analysis of the surface imaging device 2 and the onion by the transmission spectrophotometer 3 Through a comprehensive judgment output D (see FIGS. 2 and 4), which is a combination of the judgment results of the internal properties of G, command signal data is sent to a sorting device and a fruiting device (not shown), and the onion G quality judgment selection Is done.

Next, the operation of the transmissive optical gate unit 1 for measuring the external abnormalities (rots, scratches), internal abnormalities (rots) and internal properties (sugar content) of the onion G will be described.
Here, with respect to the part name of the onion G, the measurement-required part, and the measurement-unnecessary part, the scale leaf is the measurement-necessary part, and the first measurement-unnecessary part is the protective leaf (leaf, epidermis (see UN1 in FIGS. 3 and 4). ) And the root of the whiskers, and the second measurement unnecessary part is the neck (see the bud (see UN2 in FIGS. 3 and 4)) and the root. In addition, the epidermis which peeled off from the epidermis and scales is used as the epidermis.
For example, let I be the transmitted light intensity level of each part of the onion G by the transmissive light gate portion 1,
A condition defined by the following inequalities (a) to (c) is set with a preset threshold value Ta> Tb.

(A) When there is no onion G (I> Ta)
(B) When protecting leaves or roots (Ta>I> Tb)
(C) Neck (bud) or root or scale leaf (Tb> I)

(1) Presence / absence of object to be measured, detection of protective leaves and hair roots When there is no onion G and the transmitted light intensity level I is lower than Ta (Ta> I), the transmission type optical gate 1 It means adhesion of dust or the like to the light emitting elements P1, P2,... And the light receiving elements R1, R2,.
Further, when the transmitted light intensity level I is lower than Ta (Ta> I) in the state where there is the onion G, the protective leaf or the root of the hair can be detected.
(2) Removal of Protective Leaf and Beard Root Parts by Light Transmission Transmitted light intensity level I that transmits light through the protective leaf or hair root is I> Tb, that is, transmitted light higher than Tb is removed.
(3) Detection of the shape of the onion body When the transmitted light intensity level I is Tb> I, that is, transmitted light lower than Tb, it is regarded as light shielding.

As described above, the first measurement unnecessary part is determined by satisfying the condition (b).
The second measurement unnecessary portion is determined when the above condition (c) is satisfied and the following additional conditions are satisfied.
As an example of the additional condition, the binarized image of the onion G (part satisfying the condition (c) above and part satisfying the conditions (a) and (b) not satisfying the condition (c)) A contour is obtained and the contour line is described by a Fourier descriptor to remove high frequency components. This low frequency component is close to a circular shape with uneven contours.
As an example of another additional condition, an outline is obtained from a binarized image of an onion G with respect to an analytical geometric model (circle, ellipse, etc.) for a predetermined shape of the onion G, and the coordinates thereof are minimized. Fitting by multiplication.

The above method is a known shape determination algorithm, and removes protrusions such as sprouts. However, in the onion G having a small diameter, the distance that light passes through the peripheral region is also reduced in proportion to the diameter, and the transmitted light is reduced. The intensity level I is also increased. Therefore, the actual onion G is evaluated to be less than the diameter of the measurement-required part.
In particular, since the onion G having a small diameter has a low light shielding degree with respect to the light receiving surface of the light receiver 33 of the transmission spectrophotometer 3, in order to solve such a problem, the measured diameter of the onion G is The diameter needs to be multiplied by a diameter correction coefficient to correct the diameter, but this diameter correction coefficient can be obtained in advance by experiments.

  The transmission type optical gate unit 1 removes unnecessary portions by the above method, calculates the diameter of the onion G, and is more effective than the size at the height of the light receiving surface of the light receiver 33 of the transmission type spectrophotometer 3. The accumulated area is calculated and the transmitted light intensity of the pixels in the effective accumulation area is integrated with the transmission spectrophotometer 3, and the accumulated transmitted light intensity signal B for controlling the saturation of the spectrum, the spectrophotometer measurement timing, The accumulation start point and the accumulation time as size T are output, and the camera measurement timing and size TC are output to the surface imaging device.

In the above, protrusions such as buds are removed by a known shape determination algorithm or the like. For example, in the block diagram showing the signal processing by the transmission type optical gate unit 1 in FIG. When passing through the positions of the light emitting element group P and the light receiving element group R, the two-dimensional transmitted light intensity data of the onion G is obtained by the transmitted light intensity (S1 to Sn) which is the Y axis and the clock signal CL synchronized with the conveyance of the X axis. It has gained.
However, the light receiving elements corresponding to the same vertical width of the light receiving surface of the light receiver 33 of the transmission spectrophotometer 3 (hereinafter referred to as “light receiving surface vertical width”) H are R2 to R5, and transmitted light. The light receiving element output waveform indicating the intensity is S2 to S5.
For example, with respect to S1 to S6 including the periphery of the light receiving element output waveforms S2 to S5, if the effective accumulation region is calculated by removing projections such as buds by filtering of this region, the processing speed is increased.
An effective accumulation region is calculated, and the transmission spectrophotometer 3 is integrated with the transmitted light intensity signal B for controlling the saturation of the spectrum obtained by integrating the transmitted light intensities of the pixels in the effective accumulation region, and the spectrophotometer measurement timing size T Output a certain accumulation start point and accumulation time.

(Measurement judgment of onion G with relatively uniform size and shape)
In FIG. 4, the light receiving elements corresponding to the same vertical width as the light receiving surface vertical width H are R2 to R5, and are the light receiving element output waveforms S2 to S5.
The width of the bud UN2 of the onion G having the maximum selection criterion enters the gap S2 to S5 in the process of being conveyed and satisfies the condition (b), and all of S2, S3, S4 and S5 on the X axis The moment when the condition (c) is satisfied becomes the accumulation start point, and all of them become the effective accumulation area and the accumulation time during the period (c).

(Measurement judgment of onion by light receiving element gap)
The minimum unit as the Y-axis of the transmission type optical gate unit 1 can be constituted by two light receiving elements. For example, the two units of the transmission type optical gate unit 1 can pass so that the maximum width of the onion G buds can be transferred. The element gap is arranged with a gap substantially equal to both ends of the light receiving surface vertical width H, and when both of the two element output signals satisfy the condition (c), that is, two logical products are obtained, The onion G size is obtained by counting the clock signal CL synchronized with the X-axis transport while the onion is shielded from the element. The accumulation start timing and effective accumulation time calculated from the speed of the clock CL are obtained. By setting it in the transmission spectrophotometer 3, it is possible to perform measurement judgment of internal abnormalities and internal properties from which a measurement unnecessary portion has been removed.
The above-described method has an advantage that the transmission type optical gate unit 1 becomes small in an on-line type non-destructive spectroscopic measurement apparatus as a dedicated machine in which the type of object to be measured is fixed.
However, in order to respond quickly to the types of objects to be measured and various shapes, a transmission type optical gate in which the gap between the light receiving elements R1, R2,. The portion 1 is more advantageous.

(Specify the height of the spectrophotometer light emitting and receiving part)
From the contour obtained from the binarized image of the onion G by passing the position of the light emitting element group P and the light receiving element group R of the transmission type optical gate unit 1 by the conveying device C, the onion G of the minimum size selected as a non-defective product The height of the center of the onion G is calculated on the Y-axis, and the center height of the onion G is set to the center of the optical axis of the light receiving surface of the light receiving device 33 of the transmission spectrophotometer 3 by the light projection / reception elevation unit 39 shown in FIG. By automatically setting according to the above, it is possible to perform all spectroscopic measurement of the onion G from the minimum size to the maximum size.
This is because, when the light from the irradiated spectrophotometer light source 37 passes through the onion G, it is diffusely reflected inside the onion G and comes out to the outside (light receiving part side), so that it is transmitted regardless of the size of the onion G. Since the light contains internal information, the internal properties are measured and determined using a multivariate analysis method or the like.

  Even when the height of the light projecting / receiving unit of the transmission spectrophotometer 3 is changed by the light projecting / receiving elevation unit 39 as described above, the transmission light gate unit 1 is configured as shown in FIGS. 3 and 4, for example. By increasing the number of light receiving elements R1, R2,... On the Y axis (height direction) so as to cover the object to be measured of the maximum size, The structure of the drive system and the mechanical system does not become complicated and large like the configuration in which the height of the optical axis is mechanically changed, and the configuration can be simplified.

(Measurement and measurement of wrinkles with tufts)
As an example of the case where the object to be measured is not the onion G, measurement of the sugar content of the wrinkled rice cake will be described.
In online measurement using the transmission spectrophotometer 3, a Teflon (registered trademark) conveyor or the like that does not have steep spectral characteristics is used as the transport device C, and the transmission optical gate unit 1 and the transmission spectrophotometer 3 are loaded. A light receiving unit is installed in a direction perpendicular to the conveyance direction (left and right), and measurement determination is performed by spectrum analysis using transmitted light.
In the measurement, the stem of the tuft is directed to the center of the conveying device C in the direction of travel, and the wide part of the tuft is divided and measured about 10 times with the transmission spectrophotometer 3, but depending on the tuft, In some cases, there is a strong light leak from the gap, and this is measured in advance by the transmission type optical gate 1 to determine the number of divisional measurement when the transmission type spectrophotometer 3 is read. Reading can be performed by closing the high-speed shutter of the spectrophotometer 3 so that the spectral characteristics are not saturated.
In this way, the measurement of the portion where the high-speed shutter is closed is not performed, but there is no problem when viewed from the whole cocoon.

The number of saturations / number of divided measurements (%) represents the density of the cocoon bunches.
For example, when removing the stem portion of the tuft with a tuft, if the light receiving element group corresponding to the vertical width H of the light receiving surface is R3 to R8, the stem of the straw is thin, and one or two light receiving elements in the range of R3 to R8 The stem of the tufted cocoon can be removed by taking the logical product of the fact that the output circuit waveforms S3, S4, S5, S6, S7, and S8 are shielded by the fruit of the cocoon (true). .
The point in time when all of S3, S4, S5, S6, S7, and S8 on the X-axis become (true) is the accumulation start point, and the period of all (true) is the effective accumulation region and the accumulation time.

  In this way, in the step of integrating the transmitted light within the effective accumulation region, a check for saturation by strong light is performed, and the transmission spectrophotometer 3 does not measure the object to be measured. If there is a saturated portion in the object to be measured, the transmission spectrophotometer 3 can increase the measurement work efficiency by closing the high-speed shutter at that timing and not measuring that portion.

Next, an example of variations of the transmissive optical gate unit 1 will be described.
The transmission type optical gate unit 1 is not limited to the configuration shown in FIG. 3, and the transmission type optical gate unit 1 includes, for example, a light emitting element group P and a light receiving element group R as shown in FIG. A configuration in which the focal points are arranged at the center, a configuration in which light is projected and received in the vertical direction as shown in FIG. 7B, and the like may be used. The arrangement of the group R can be determined and used. In addition, an element having a light emission wavelength of two or more wavelengths is optically used in parallel in the light emitting element group P, and a light reception signal is obtained by time division for each wavelength, and the shape of the object to be measured is determined from each two-dimensional image. The transmissive optical gate portions 1 having different wavelengths of the light emitting element group P are densely arranged on the transport device C for each wavelength, and each two-dimensional image is determined to determine the shape of the object to be measured. A determination may be made.

  A plurality of transmission optical gate units 1 may be installed. For example, a plurality of light emitting element groups P and light receiving element groups R having different emission wavelengths are installed upstream of the transmission spectrophotometer 3 in the transport direction. Are used to select a signal from the image analysis unit 4 having the optimum wavelength for the object to be measured, or to calculate the spectroscope from all the information. And the camera image analysis unit 32 can perform computation and output a comprehensive determination. The plurality of transmission type optical gate portions 1, 1,... Are arranged in a single casing, and can be used as a transmission type optical gate portion in which light emitting elements and light receiving elements having different emission wavelengths are effectively arranged. Good.

  As described above, the on-line nondestructive spectroscopic analyzer of the present invention measures the transmitted light intensity distribution of the object to be measured shown in S1 to Sn as shown in FIG. 4 in a two-dimensional manner, as shown in FIG. In the light receiving unit circuit 8, saturation countermeasures are performed by FETs, and the light emitting element group P and the light receiving element group R of the transmission type optical gate unit 1 are installed on the upstream side of the surface imaging device 2 and the transmission type spectrophotometer 3 to transmit the transmitted light. For the intensity level and shape, logical filtering is performed with a predetermined shape pattern of the object to be measured, the measurement unnecessary part is removed, and the effective measurement area of the measurement necessary part is calculated from the two-dimensional transmitted light intensity data, Accumulated transmitted light that outputs the camera measurement timing and size TC to the surface imaging device 2 and controls the saturation of the spectrum obtained by integrating the transmitted light intensity of the pixels in the effective accumulation region to the transmission spectrophotometer 3. Intensity signal B By outputting fine spectrophotometer measurement timing size T, it is to improve the determination accuracy.

Further, the transmission type optical gate unit 1 can practically reduce the influence of dust and the like by a strong light source and saturation processing of the light receiving unit, and the output waveform (S1 to Sn) of the light receiving element group R is transmitted through the object to be measured. Although handled as light intensity, an ND filter plate having a known attenuation characteristic is switched in front of, for example, the light receiving element group R, sampled when there is no object to be measured, and recorded as reference data. The two-dimensional transmittance characteristics of the measurement object at the wavelength of the light emitting elements (P1 to Pn) are obtained as S1 to Sn) = measurement object data / (ND filter data × attenuation rate (real number notation)).
As a result, the deterioration of the light emitting elements (P1 to Pn) with time, the contamination of the optical system, the individual light emitting elements, the optics of the light receiving elements and the sensitivity of the electronic circuit can be corrected.
Furthermore, if it is necessary to perform measurement with higher accuracy, calculation processing may be performed with the transmitted light intensity as the transmittance.

A Measuring object conveyance direction B Integrated transmitted light intensity signal C Conveying device CL Clock signal D Comprehensive judgment output G Onion (measurement object)
H Light receiving surface length I Transmitted light intensity L Total length (including onion buds)
LN measurement required part length L1 projection light L2 received light P light emitting element group R light receiving element group P1, P2, P3,..., P20 light emitting elements R1, R2, R3,..., R20 light receiving elements S1, S2, S3,. Light receiving element output waveform Ta, Tb Threshold value T Spectrophotometer measurement timing size TC Camera timing size UN1 Epidermis (first measurement unnecessary part)
UN2 bud (second measurement unnecessary site)
V1 Anti-saturation bias voltage V2 Level shift bias voltage V3 Light emitting element current control voltage 1 Transmission type optical gate unit 2 Surface imaging device 3 Transmission type spectrophotometer 4 Optical gate image analysis unit 5 Collimator lens 6 Hood 7 Projection unit circuit 8 Light-receiving unit circuit 9 Light-emitting element drive circuit 10 Preamplifier 11 Anti-saturation FET
12 Subsequent amplifier 13 Zero point correction circuit 14 Light-emitting element drive pulse 15 Zero point correction pulse 16 Analog multiplexer 17, 18 A / D converter 19 Command signal data line 20 One-chip CPU
21 Camera 22 Projector 23 Side mirror 24 Camera interface 31 Spectrometer and control unit 32 Spectrometer calculation unit and camera image analysis unit 33 Light receiver 34 Optical aperture 35 Optical aperture actuator 36 Optical fiber 37 Light source 38 Halogen lamp 39 Light projection and reception elevation unit

Claims (2)

An on-line nondestructive spectrophotometer that uses a transmission spectrophotometer to measure the internal properties of an object to be measured , including parts that do not require measurement, which are sequentially transported in a state of unevenness by a transport device,
The transport device outputs a clock signal synchronized with transport,
A light emitting element group installed on the upstream side of the transmission spectrophotometer in order to measure the transmitted light intensity distribution of the object to be measured two-dimensionally, and light reception for receiving light emitted by the light emitting element group A transmission type optical gate unit having an element group is provided. The transmission type optical gate unit detects a first measurement unnecessary portion of the measurement object whose transmitted light intensity is higher than a predetermined threshold, and detects only by the transmitted light intensity. The second measurement-unnecessary part of the object to be measured that is not detected is detected by transmitted light intensity and shape determination, and the size and effective measurement of the measurement-required part of the object to be measured are excluded except for the first measurement-unnecessary part and the second measurement-unnecessary part. The integrated transmission light intensity signal for controlling the saturation of the spectrum obtained by calculating the area and integrating the transmission light intensity of the pixels in the effective accumulation area to the transmission spectrophotometer, and the clock signal On-Line nondestructive spectrometer for outputting an accumulation starting point and the storage time synchronized.
In order to measure the surface abnormality of the object to be measured on the downstream side in the transport direction with respect to the light emitting element group and the light receiving element group of the transmission type optical gate unit and on the upstream side or downstream side in the transport direction with respect to the transmission type spectrophotometer. A surface imaging device having a camera for imaging the object to be measured and a projector for illuminating the object to be measured, wherein the vicinity of the image center of the object to be measured is from the transmission type optical gate unit to the surface imaging device. The on-line type nondestructive spectroscopic analysis apparatus according to claim 1, wherein an imaging start trigger signal and a size synchronized with the clock signal are output so as to be positioned at a center of an image area of the camera.

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