JP3710596B2 - Fruit and vegetable judgment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fruit and vegetable determination apparatus that gives impact sound to fruits and vegetables, detects the state of propagation of the impact sound in the fruits and vegetables, and determines the hardness of the fruits and vegetables.
[0002]
In particular, it is useful for determining the ripening degree of a fruit and the degree of pain.
[0003]
[Prior art]
The conventional ripening degree of fruits and vegetables, the condition of pain, etc. are determined at the time of harvest shipment or sale by determining the appearance shape and color of the target fruit and vegetable and extracting the fruit and vegetable sample, destroying the sample, and aging in the fruit and vegetable This is done by measuring the situation and sugar content. The determination based on the appearance requires many years of experience, and the destruction determination based on sampling is wasteful because the destroyed fruits and vegetables cannot be sold as products. Especially for fruits, etc., there is a lapse of time at the time of harvest shipment and market sale, and the ripening of the fruits has progressed during that time, so at the time of harvest shipment, the time when ripening is expected to progress before the market sale When harvested in the market and sold on the market, it must be provided as a fully aged product without decay.
[0004]
Various determination apparatuses have been developed and used as a method for accurately and uniformly determining the ripening determination of fruits and vegetables without relying on experienced persons. A typical example of this determination apparatus is a water maturity determination apparatus.
[0005]
The maturity level of the watermelon is judged by a skilled producer or salesman by hitting the watermelon by hand and judging from the feel and sound quality and sound quality at that time. Is used to collect the impact sound transmitted through the watermelon using a microphone and analyze the frequency of the collected sound to determine maturity. The sound that propagates through the watermelon can be divided into those that propagate through the hard skin of the surface of the watermelon and those that propagate inside the watermelon. To determine the maturity of the watermelon, the sound that propagates inside the watermelon Must be collected and frequency analyzed. However, in the watermelon, a portion (red portion) that is generally eaten inside the watermelon is formed immediately after ripening, and contains a lot of moisture. For this reason, the sound propagating through the watermelon is attenuated by the moisture. On the other hand, the surface of the watermelon has an epidermis and a part of the epidermis that does not eat in general (white part) of a certain thickness, and this epidermis and a part that does not eat in general (hereinafter referred to as the epidermis part) are transmitted. Sound has a good propagation rate due to its hard fruit quality. Thus, after collecting the sound that is propagated inside the skin portion of the watermelon, when frequency analysis, sound propagated through the skin portions a sufficient amount required for analysis is obtained, which is propagated inside The amount of sound is small and is superimposed on the sound propagated through the epidermis, making it difficult to analyze the epidermis and internal propagation. In addition, as the ripening of watermelon progresses, the epidermis part will maintain the fruit state at the time of harvest for a long time, but the inside will be cracked and moisture content will be reduced, so the ripening inside the watermelon will be judged. The maturity is determined only by frequency analysis using sound propagating mainly through the skin part.
[0006]
However, fruits that show a different growth state from the watermelon, such as melon, are generally hard to eat from the time of fruiting to just after harvesting, and cannot be eaten as they are. Therefore, the inside ripening progresses by leaving it to stand for a certain period after harvesting, and the state of progress of the ripening is judged to be shipped and marketed. Even if a melon tracing the growth process is used in the same determination device as the watermelon, both the inside of the melon and the sound propagating through the epidermis are detected and the maturity cannot be determined. There is no other method than judging experience and the degree of ripening inside by destroying the melon, and a lot of skilled people are required for ripening judgment at the collection point where a large amount of fruits from different producers collect. Is desired.
[0007]
[Problems to be solved by the invention]
As described above, the edible part of the fruit is hard until immediately after harvesting, ripening with a post-harvest ripening period, and ripening judgment is not only judged from experience by skilled workers, but also for judgment of large quantities of fruits with different producers A large number of skilled workers are required, and there is a problem that a lot of time is required for the shipping judgment work.
[0008]
[Means for Solving the Problems]
The present invention relates to an impact providing means for striking an object to be determined and applying an impact sound to the object to be determined, and a sound collecting means for collecting an impact sound propagating through the non-edible skin portion and the internal edible portion of the object to be determined. The frequency analysis means for analyzing the propagation vibration frequency of the object to be determined based on the impact sound propagated through the skin part and the edible part of the determination part collected by the sound collecting means, and the frequency analysis means And calculating means for extracting two different peak value frequencies from the propagation vibration frequency and calculating a frequency value difference and a wave front value difference between the two different peak values, and the determination target calculated by the calculation means a fruit or vegetable determination device for an aging determination of the determination target object by using the frequency value differences with crests value difference between the two peak values of different transmitted vibration frequency of the object.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is to provide a certain ripening period after harvesting, although the edible part inside the fruit is hard and not edible during the period from fruiting to harvesting like fruits such as melon among fruits and vegetables. As a result, aging of the edible portion inside the fruit proceeds and the edible portion is provided for food. The aging of the edible part spreads from the central part of the fruit to the hull side, and as the maturation progresses, it ripens to just inside the hull. As the ripening progresses to rot, the outer skin surface also becomes soft. As a result of repeating a number of experiments, the inventor of the present invention has been made by paying attention to the fact that the propagation vibration frequency of the fruit changes due to the progress of ripening inside the fruit. .
[0010]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a fruit and vegetable determination apparatus according to the present invention.
[0011]
In the figure, reference numeral 11 denotes an object to be judged such as melon. The determination object 11 is placed on a determination object fixture (not shown). A hammer 12 is provided in the vicinity of the determination target fixture and generates an impact sound by hitting the determination target 11. The hammer 12 has a central portion fixed, one end is a hitting portion for hitting the object 11 to be determined, and the other end is a hammer driving portion for lifting the hitting portion by a predetermined angle. Then, the hit point portion is lifted by a predetermined angle, and then the hit point portion is dropped in an arrow direction indicated by a dotted line in the figure to hit the object to be determined 11 with a predetermined force. The impact sound generated by the hammer 12 and the determination object 11 is propagated to the outer skin portion of the determination object 11 and the edible portion inside. Two sound collectors 13 and 14, such as a microphone that collects the impact sound, are attached so as to be in close contact with the object to be judged 11. The analog impact sound signal propagated through the object to be judged 11 collected by the sound collectors 13 and 14 is supplied to the amplifier 15 to be amplified to a predetermined impact sound signal. The amplified impact voice signal in this amplifier 15 by the AD converter, that converts an analog signal into a digital signal. At the time of conversion to the digital signal, only the vibration frequency of the impact sound generated by the determination object 11 and the hammer 12 collected by the sound collectors 13 and 14 is converted into a digital signal, and the other signals to be received are converted. The vibration frequency of the sound collected via the determination unit 11 is removed. The vibration frequency of the impact sound converted into a digital signal by the AD converter 16 is supplied to a frequency analyzer 17 composed of an electronic computer or the like. In this frequency analyzer 17, the first impact vibration propagated through the outer skin of the object 11 collected by the sound collectors 13 and 14 and the outer skin portion in the vicinity thereof and the vibration frequency that gradually attenuates (hereinafter referred to as the outer skin). A partial propagation vibration frequency and a vibration frequency that is gradually attenuated (hereinafter referred to as an edible partial propagation vibration frequency). . The peak values of both propagation vibration frequencies of the outer skin portion and the edible portion are obtained.
[0012]
At the time of harvesting, the melon that is the judgment object 11 is hard in both the outer skin part and the edible part, and the propagation vibration frequency of both parts shows substantially the same vibration frequency. However, as the aging of the edible part proceeds, Although it does not change, the hardness of the edible part decreases and the propagation vibration frequency changes. That is, as the aging of the edible part progresses, the propagation vibration frequencies of the outer skin part and the edible part differ, and frequencies having different peak values can be obtained. The frequency analyzer 17 calculates the frequency interval (referred to as frequency value difference) between the peak value frequencies of the different peak values and the frequency intensity difference (referred to as wave front value difference) between the peak values, thereby determining the maturity of the determination target 11. It can be used for determination.
[0013]
The correlation of the determination of the maturity level of the object to be determined 11 from the difference in the peak value of the propagation vibration frequency between the outer skin part and the edible part will be described with reference to the graph of FIG. 2 showing the frequency and frequency intensity distribution.
[0014]
FIG. 2A shows the propagation vibration frequency of the first day immediately after the harvest of the melon that is the determination object 11. In the melon immediately after harvesting, the outer skin part and the edible part have almost the same hardness, and the propagation vibration frequency thereof has the same frequency. The peak value obtained by analyzing this frequency by the frequency analyzer 17 is one. Next, FIG. 2B shows the propagation vibration frequency on the fifth day from the harvest of the melon that is the determination object 11. Melons that have passed 5 days after harvest have been ripened in the edible part, are softer than the outer skin part, and have different propagation frequencies. When this different frequency is analyzed by the frequency analyzer 17, there are two peak values. The interval difference a and the wave front value difference b between the frequency values of the two peak values are calculated to indicate the ripening degree of the melon.
[0015]
In other words, the aging of the melon edible part starts from the central part of the melon and gradually expands to the outer skin part. Therefore, the frequency value difference a of the two peak values in accordance with aging is enlarged to the outer skin portion, the greater the frequency value difference a. Further, the wave front value difference b between the frequencies of the two peak values becomes smaller as the aging is expanded.
[0016]
Accordingly, the frequency analyzer 17 detects two peak values of the propagation vibration frequency of the outer skin portion and the edible portion, calculates a frequency value difference a and a wave front value difference b of the two peak values, and is set in advance. Further, the relationship between the frequency value difference a and the wave front value difference b is used. If the relationship is within the range of the relationship, the shipment is allowed. If the relationship is exceeded, the shipment is rejected due to excessive aging and the relationship is determined. When it is not satisfied, it is easy to determine ripening again, and it is possible to provide a fruit and vegetable determination device that can determine the ripening degree of a fruit without depending on an expert.
[0017]
The relationship between the frequency value difference a and the wave front value difference b of the peak value of the propagation vibration frequency between the outer skin portion and the edible portion of the determination object 11 is obtained as a correlation with a predetermined number of samples, and the frequency analyzer 17, and the determination of the maturity of each of the objects to be determined 11 is possible by comparing and determining each time the propagation vibration frequency of each object to be determined 11 is detected.
[0018]
In addition, since the aging speed and range vary depending on the size of the determination object 11, a weight measuring device for the determination object 11 is provided in the determination object fixture on which the determination object 11 is placed, and this weight By correcting the two propagation vibration frequencies of the determination object 11 by the frequency analyzer 17 with the weight value measured by the measuring instrument, it is possible to eliminate the error in the ripening degree and the aging range due to the size of the determination object 11. it can.
[0019]
Furthermore, the determination target object fixture determination target object 11 of the present invention provided on a plurality conveyors, by Rukoto circulated move the conveyor, automatically determine the amounts of the determination target object, the frequency and the results It is also clear that the output can be automatically selected by outputting from the analyzer and transmitting the quality of the shipment for each object to be judged.
[0020]
【The invention's effect】
As described above, according to the present invention, a predetermined impact sound is given to the fruit without discriminating the ripening degree of the fruit by an expert, and the peak of the propagation vibration frequency of the impact sound of the outer skin part and the edible part of the fruit is given. By determining the maturity of the object to be determined using the relationship between the frequency value difference and the wave front value difference, it has become possible to easily realize a large amount and efficient selection or discrimination.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a fruit and vegetable determination apparatus according to the present invention.
FIG. 2 is a graph showing the relationship between the peak value frequency and the frequency intensity of the propagation vibration frequency of fruits and vegetables measured by the fruits and vegetables determination apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... To-be-determined object, 12 ... Hammer, 13, 14 ... Sound collection microphone, 15 ... Amplifier, 16 ... AD converter, 17 ... Frequency analyzer.

Claims (3)

An impact providing means for striking the object to be judged and giving an impact sound;
Sound collecting means for collecting an impact sound that propagates through the skin portion and the edible portion of the object to be determined;
Frequency analysis means for analyzing a propagation vibration frequency of the object to be determined based on an impact sound that has propagated through the skin portion and the edible part of the object to be determined collected by the sound collecting means;
Extracting two peak values different frequencies from the transmitted vibration frequency captured by the said frequency analysis means, comprising a calculating means for calculating a frequency value difference and crests value difference of the two different peak values, a,
The fruit and vegetable determination apparatus characterized in that the determination object is determined to be matured using a frequency value difference and a wave front value difference between two peak values having different propagation vibration frequencies of the determination object calculated by the calculation means. The maturity determination of the object to be determined is performed using a correlation in which a frequency value difference between two different peak values calculated by the calculation unit increases and a wave front value difference decreases. Fruits and vegetables judgment device. The frequency value difference between two different peak values calculated by the calculating means indicates the maturation range of the object to be determined, and the wave front value difference indicates the maturity of the object to be determined, and the frequency value difference and the wave front value difference. The fruit and vegetable determination apparatus according to claim 1, wherein the aging determination of the determination object is performed using the correlation of

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