JPH0735730A - Method for deciding ripeness of fruit by hammering sound or vibration - Google Patents

Abstract

PURPOSE:To allow quick and accurate decision of the ripeness of fruit even at a production field by hitting the fruit lightly with a hammer having an appropriate mass CONSTITUTION:A light hitting apparatus 1 is supported by griping a grip 12 with one hand and a fruit A is held by the other hand. A vibration detector 2 and a size detector 3 are then applied to the fruit A and a trigger 11 is pulled. Consequently, a hammer 8 of appropriate mass is actuated by the pressure of a spring 9 to hit the fruit A lightly. Pressure of the spring 9 is regulated by means of a regulation knob 10. Hammering sound and vibration are captured by the vibration detector 2 which delivers a signal through a signal amplifier to a frequency analyzing section where the signal is processed and a resonance frequency (peak frequency) is measured. An operating/deciding section decides the ripeness based on the mass of the fruit A estimated from the data received from the detector and a predetermined value operated from the resonance frequency and the decision results are displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for fruits and vegetables whose fruit ripeness cannot be judged only by their appearance. The present invention relates to a method for determining the ripeness of fruits or the like by hitting or vibrating so that the maturity of the fruits or the like is determined by a numerical value calculated from the resonance frequency at that time and the mass of the fruits or the like.

[0002]

2. Description of the Related Art Conventionally, research results have been obtained that the numerical value obtained from the secondary resonance frequency and the mass of fruits has a high correlation with the ripeness (hardness) of fruits. For example, non-contact vibration is applied to a fruit hung with a thread while changing the sound wave frequency by a speaker, and the resonance frequency at that time is sequentially measured using an accelerometer over several orders, and the second frequency is counted from the low frequency.
The number that can be used to judge the ripeness is calculated from the second resonance frequency and the mass of the fruit measured separately. It has also been attempted to determine the ripeness only by the resonance frequency, but even if the fruit has a constant maturity, the larger the mass, the lower the resonance frequency, so the mass of the fruit must be almost constant. ,
It was difficult to judge the maturity.

In addition, a tapping type watermelon cavity determination device has been devised. This is to hit a point on the equator of a fruit with a hammer, detect the striking sound with three microphones placed at equal intervals on the opposite side of the equator, and determine the size of the cavity from the difference in transmission time and the disturbance of the waveform. To do.

[0004]

Generally, fruits and the like have irregular sizes and shapes, and the added value is enhanced by dividing the fruits into a certain scale of quality. At the production and distribution site, it is required to make nondestructive, rapid and accurate determination of the maturity level. Therefore, the maturity determination method as described above has been studied, but with the determination method or device such as the former, it takes a long time to support the fruit and measure the resonance frequency, so that it can be used in the field. Not suitable. Further, in the latter method described above, it was difficult to determine the ripeness when fruits having different masses were mixed. As described above, at present, there is no method or apparatus for quickly and accurately determining the degree of maturity at the production site by tapping sound and vibration.

The present invention has been made to solve the above problems. That is, in the present invention, of course, after harvesting, it is in a tree or napped state before harvesting in a field or a house, internal quality cannot be judged only by appearance, for example, pine, or ripening after harvesting in an immature state Although it is shipped, the degree of ripening cannot be determined only by the appearance, for example, targeting fruits and vegetables such as pear, hitting the fruit with a hitting body of an appropriate mass with respect to the mass of the fruit,
It is an object of the present invention to provide a judgment method for judging the ripeness of a fruit by a numerical value calculated from the resonance frequency at that time and the mass (size) of the fruit.

[0006]

In order to achieve the above-mentioned object, the present invention stabilizes the secondary resonance frequency when a fruit is hit with an impacting body having an appropriate mass with respect to the mass of the fruit or the like. Found that can be generated by
The fruit is hit with an impacting body with an appropriate mass to the mass of the fruit etc. to generate tapping sound and vibration, and at the same time as the hitting, the ripeness is judged by the resonance frequency and the value calculated from the mass of the fruit etc. It is characterized by doing so.

[0007]

With the above-described means, the method for judging the ripeness of fruits and the like by tapping sound and vibration of the present invention is to measure the secondary resonance frequency instantly by tapping the held fruits with a hammer having an appropriate mass. At the same time, the mass (size) of the fruit is measured, and the ripeness is quickly judged by the numerical value calculated from both.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a block diagram of a method for determining the ripeness of fruits and the like according to the present invention, and FIG. 2 is a schematic side view of a portable tapping device, the basic configuration of which is as follows. Tapping device 1 for tapping fruit A, tapping sound or vibration detector 2 (microphone or accelerometer), signal amplifier 4, frequency analysis unit 5, mass (size) detection unit 3 of fruit A, calculation / judgment unit It is composed of 6. When the light tapping device 1 is used as a portable type, it is a pistol type that can hammer out a hammer 8 with spring pressure 9 and the like, and a vibration detector 2 and a fruit size detector 3 are integrated into a handy shape. To do.

In the case of stationary use, the vibration detector 2 and the load converter need not be integrated as long as the tapping device 1 has a mechanism capable of hammering out the hammer 8 with spring pressure 9 or the like. Can be configured. The hammer 8 has an appropriate mass according to the mass range of the fruit A. For the vibration detector 2, a microphone, an accelerometer or the like is used. Whether the mass of fruit A is detected directly by a load converter,
Alternatively, a size detector 3 including a lever and a potentiometer detects a curvature or the like, and a value estimated from this is used.

As a method of supporting the fruit A, the fruit A is held by a finger in a portable type. Also, when using stationary,
Hold using the required equipment. The numerical value (J) used for judging the maturity is calculated by the following formula. J = K · m · ω ² (value corresponding to spring constant) or J = K · m ^2/3 · ω ² (value corresponding to Young's modulus) where m: mass of fruit, ω: resonance frequency, K: constant The reason for using the above formula is based on the test result that a high correlation is recognized between the ripeness of fruits and the magnitude of elasticity, which can be used for judging ripeness.

Next, the configuration of the portable tapping device 1 shown in FIG. 2 will be described. The portable tapping device 1 has a so-called pistol shape. Then, the vibration detector 2 including an accelerometer or the like is attached to the tip of the main body portion 7 via a vibration isolator, and the fruit A when the vibration detector 2 is pressed against the fruit A.
A size detector 3 composed of a lever and a potentiometer is installed so that the size of can be detected. Further, a hammer 8 is provided on the main body portion 7 so as to be hammered out by the spring pressure of the spring 9 to tap the fruit A, and the spring pressure of the spring 9 is adjusted by the spring pressure adjusting knob 10. . A trigger 11 for hammering out the hammer 8 is provided, and a grip 12 is provided behind the trigger 11.

In the portable tapping device 1 having such a structure, the grip 12 is held by one hand to support the tapping device 1, and the fruit A is held by the other hand and the vibration detector 2 and By pressing the detector 3 against the fruit A and pulling the trigger 11, the hammer 8 is struck by the spring pressure 9 or the like, and the fruit A
Tap. This vibration detector is installed as indicated by reference numeral A. The vibration generated when the fruit A is tapped by the hammer 8 is captured by the vibration detector 2, processed by the frequency analysis unit 5 via the signal amplifier 4, and the resonance frequency (peak frequency) is measured. The calculation / determination unit 6
At, the mass of the fruit A estimated from the data from the size detector 3 and a predetermined calculation value from the resonance frequency are obtained, and based on this, the maturity determination is performed and the determination result is displayed.

In order to obtain a stable peak frequency during measurement with the portable tapping device 1, the hammer 8 for tapping the fruit A has a mass of, for example, pear of 150 to 4g when 200g, 280-
It has been found that when it is 430 g, it is preferably about 7.5 g.

[0014]

As described above, according to the method for determining the ripeness of fruits and the like by hammering sound and vibration of the present invention, the fruits and the like are struck and struck by an impacting body having an appropriate mass with respect to the mass of the fruits and the like. Sound and vibration are generated, and the ripeness is determined from the resonance frequency and the value calculated from the mass of fruits, etc., so that the ripeness can be determined quickly and accurately from the outside of the fruit in a non-destructive state. it can.

Further, the method of the present invention can be easily implemented as a device, can be miniaturized and can be portable, and can be used to determine the ripeness of fruits and vegetables before harvest for the purpose of timely harvesting / selective harvesting.
Suitable for use at cultivation sites. Furthermore, it can be easily applied to fruit-pickling facilities, general markets, test equipment, etc., and is highly versatile.

[Brief description of drawings]

FIG. 1 is a block diagram of a method for determining the maturity of fruits and the like according to the present invention.

FIG. 2 is a schematic side view of a portable tapping device according to the present invention.

[Explanation of symbols]

 1 light tapping device 2 vibration detector 3 fruit size detector 4 signal amplifier 5 frequency analysis unit 6 calculation / judgment unit 7 light tapping device main body 8 hammer 9 spring 10 spring pressure adjustment knob 11 trigger 12 grip A fruit

Claims (1)

[Claims] 1. A method for determining the ripeness of a fruit or the like by a numerical value calculated from the resonance frequency and the mass of the fruit or the like, in which the fruit or the like is hit with an impacting body having an appropriate mass with respect to the mass of the fruit or the like, A ripeness judgment method for fruits and the like by hammering sounds and vibrations, which is characterized in that a tapping sound and vibration are generated and the ripeness is judged by a numerical value calculated from the resonance frequency and the mass of the fruit and the like.