JPH04323537A - Selecting method for fish and its device - Google Patents

Abstract

PURPOSE:To provide a selecting method for tunas and its device by measuring fat amount accurately and selecting without any problem on sanitation. CONSTITUTION:A water channel 12 for feeding a tuna 16 in water, a position sensor 22 detecting the tuna 16 carried to a fixed position by being fed in water in the water channel 12, and an X-ray radiation device 20 radiating the X-ray toward the tuna 16 based on an output from the position sensor 22 are provided. An X-ray line sensor 24 detecting the X-ray penetrated amount of the tuna 16 and arranged in the orthogonal direction to the arranged direction of the water channel 12, a signal processing device 28 extracting a waveform being equivalent to a fat component from an X-ray penetrated signal waveform given by the X-ray line sensor 24, and an operation processing device 30 making operation of a fat amount from the area of the extracted waveform are provided further.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for sorting fish, and more particularly to a method and apparatus for sorting large fish such as tuna based on their fat content.

0002

[Prior Art] Conventionally, the method of sorting tuna based on fat content was as follows:
This is done visually. That is, a skilled inspector inspects the distribution of oil (fat) on the cut surface near the tail of the tuna,
The fat content in the tuna body is estimated based on its distribution and amount. There is also a method of estimating fat content by examining the distribution of fat in the tuna body cut out into a cylindrical shape.

0003

[Problems to be Solved by the Invention] However, the conventional method of sorting tuna based on fat content is based on estimation, and therefore has the drawback of not being able to accurately sort tuna. Furthermore, the conventional method of hollowing out the tuna body into a cylindrical shape has hygienic drawbacks, such as the generation of disease bacteria from the hollowed out wounds.

The present invention has been made in view of the above circumstances, and provides a method and apparatus for sorting fish that can accurately measure and sort fat content without any hygienic problems. The purpose is to

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention irradiates X-rays to fish being transported underwater, and detects the amount of X-rays transmitted by the fish using an X-ray line sensor. , a signal waveform corresponding to fat content is extracted from an X-ray transmission signal waveform obtained by an X-ray line sensor, and fish are sorted based on the area of the extracted signal waveform. The extracted signal waveform is created by subtracting the low-pass filtered waveform of the X-ray transmitted signal waveform from the X-ray transmitted signal waveform, and the extracted signal waveform area is created by integrating the extracted signal waveform over time. Find it by doing.

[0006]

According to the present invention, first, fish are transported underwater in a waterway, and the position of the fish being transported is detected by a position sensor. Next, based on the detection information from the position sensor, an X-ray irradiation device irradiates the fish with X-rays, and an X-ray line sensor detects the amount of X-rays transmitted through the fish. Next, a signal waveform corresponding to fat content is extracted by a signal processing device from the X-ray transmission signal waveform obtained by this X-ray line sensor. Here, the extracted signal waveform is created by subtracting the low-pass filtered waveform of the X-ray transmission signal waveform from the X-ray transmission signal waveform.

[0007] Then, the arithmetic processing device calculates the fat content from the extracted waveform area to measure the fat content in the fish itself. Here, the extracted signal waveform area is obtained by integrating the extracted signal waveform over time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the fish sorting method and apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a fish sorting device 10 according to the present invention, in which a water channel 12 is arranged to pass through an X-ray shield box 14.

Water 18 flows through the water channel 12 to transport the tuna 16 underwater in the direction of the arrow in the figure. In addition, the above
An X-ray irradiation device 20 is provided in the ray shield box 14, and this X-ray irradiation device 20 has an X-ray irradiation port connected to the waterway 1.
2, the tuna 16 is conveyed underwater. This X-ray irradiation device 20 is controlled to irradiate X-rays at the timing when a position sensor 22 installed below the waterway 12 detects the head 16a of the tuna 16, and also irradiates the tail 16a.
The X-ray irradiation is controlled to stop at the timing when 6b passes.

On the other hand, the X-ray line sensor 24
6 to the signal processing circuit 28. This X-ray line sensor 24 is disposed adjacent to the upstream side of the position sensor 22, and inputs an X-ray transmission signal transmitted through the tuna 16 to a signal processing circuit 28 via the cable 26. . Furthermore, as shown in FIG. 2, the X-ray line sensor 24 includes a plurality of X-ray sensor elements 2 from 1ch to nch.
4a, 24a, . . . are arranged in a row in a direction perpendicular to the transport direction of the tuna 16 and with a length that can sufficiently compensate for the width of the tuna 16. Here, since the water 18 and the lean part of the tuna 16 have substantially the same X-ray transmittance, it is possible to prevent the X-ray transmittance from changing depending on the external shape of the tuna 16. As a result, only the X-ray transmission image showing the bones and fat parts of the tuna 16 is inputted to the X-ray line sensor 24, so that the X-ray transmission image showing the bones and fat parts of the tuna 16 is inputted to the signal processing circuit 28. A transmitted signal is input.

Further, an arithmetic processing unit 30 is connected to the signal processing circuit 28 . This arithmetic processing device 30 can measure the area by integrating the image signal processed by the signal processing circuit 28. Next, the operation of the fish sorting device constructed as described above will be explained. First, tuna 16
When the tuna 16 is conveyed underwater in the waterway 12 and detected by the sensor 22, the X-ray irradiation device 20 irradiates the tuna 16 with X-rays at that timing. At this time, the output signal output from the X-ray line sensor 24 to the signal processing circuit 28 is
As shown by the solid line a in FIG. 3, the amount of X-ray transmission increases in the abdominal fat and back fat of the tuna 16, resulting in a convex waveform. Furthermore, in bone parts such as the vertebrae of the tuna 16, the amount of X-ray transmission decreases, resulting in a concave waveform. Here, since the area of the convex waveform portion has a correlation with the fat content of the tuna 16, the tuna 16 can be sorted by measuring this area.

To measure the area of the convex waveform, first, a waveform (broken line b) is created by low-pass filtering based on the output waveform of the solid line a (broken line b) in the signal processing circuit 28 shown in FIG. Next, the difference between the output waveform of the solid line a and the output waveform of the broken line b is taken to create a waveform of only the convex waveform portion shown in FIG. 4. Next, the waveform of only this convex waveform portion is integrated by the arithmetic processing unit 30 shown in FIG. 1 to obtain its area value.

The area value indicates the amount of fat in one cross section of the tuna 16, so when measuring the amount of fat in the entire tuna 16, the detection signal of the position sensor 22 described above is used as a trigger and the method shown in FIG. As shown, scanning is performed five times (any number of times is fine) and the area values obtained for each are added. Thereby, the amount of fat in the entire tuna 16 can be accurately measured without damaging the tuna 16.

[0014] Therefore, according to this embodiment, compared to the conventional method of sorting fish by estimating the fat content,
Fat content can be measured accurately and without any hygienic problems.

[0015]

Effects of the Invention As explained above, according to the method and device for sorting fish according to the present invention, X-rays are irradiated from the X-ray irradiation device to fish being transported underwater, and the X-rays of the fish are The amount of transmission is detected by an X-ray line sensor, only the signal waveform corresponding to the fat content is extracted from the X-ray transmission signal waveform obtained by the X-ray line sensor, and the fish is classified based on the area of the extracted signal waveform. Since the fat content is sorted, the fat content can be accurately measured and sorted without causing any sanitary problems.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the fish sorting device according to the present invention.

FIG. 2 is a perspective view showing the positional relationship between an X-ray line sensor applied to the fish sorting device according to the present invention and tuna.

[Fig. 3] Explanatory diagram showing an example of an X-ray transmission signal waveform

[Figure 4
】Explanatory diagram showing an example of fat extraction signal waveform

[Figure 5]
An explanatory diagram of the tuna fat extraction signal waveform created by scanning the X-ray line sensor multiple times

[Explanation of symbols]

10...Sorting device 12...Waterway 16...Tuna 18...Water 20...X-ray irradiation device 22...Position sensor 24...X-ray line sensor 28...Signal processing circuit 30... Arithmetic processing circuit

Claims (4)

[Claims] Claim 1: irradiating X-rays to fish being transported underwater, detecting the amount of X-rays transmitted by the fish with an X-ray line sensor,
Fish, characterized in that only a signal waveform corresponding to fat content is extracted from an X-ray transmission signal waveform obtained by an X-ray line sensor, and fish are sorted based on the area of the extracted signal waveform. selection method. 2. The fish selection according to claim 1, wherein the extracted signal waveform is created by subtracting a low-pass filtered waveform of the X-ray transmission signal waveform from the X-ray transmission signal waveform. Method. 3. The fish sorting method according to claim 1, wherein the extracted signal waveform area is determined by integrating the extracted signal waveform over time. 4. A waterway for transporting fish underwater; a position sensor for detecting that the fish transported underwater in the waterway have been transported to a predetermined position; an X-ray irradiation device that irradiates X-rays toward A method for sorting fish, comprising: a signal processing device that extracts a waveform corresponding to fat content from an X-ray transmission signal waveform obtained by a sensor; and an arithmetic processing device that calculates fat content from the area of the extracted waveform. Device.