JP4454415B2 - Article hardness measuring apparatus and article hardness measuring method - Google Patents

Description

  The present invention relates to an article hardness measurement apparatus and an article hardness measurement method for nondestructively measuring the hardness of articles such as fruits and vegetables.

    Conventionally, in fruits and vegetables such as fruits and vegetables, for example, by measuring the hardness of flesh such as apples, the hardness of hulls such as orange and grapefruit, and the degree of floating skin such as mandarin oranges, The quality of the internal quality and whether it can withstand storage and transportation are measured.

  As a method of measuring the hardness of such fruits and vegetables, hitherto, a load meter was pressed against the fruits and vegetables, and the spring pressure when the surface of the fruits and vegetables was broken was measured. A spring pressure type hardness measuring device is used to measure.

  However, with such a spring pressure type hardness measuring device, the surface of the fruits and vegetables will be destroyed. Therefore, in the fruits and vegetables field, the fruits and vegetables whose surfaces were destroyed for measurement must be discarded. If it is converted into a year, it is a great deal of damage.

For this reason, conventionally, the hardness of an article is measured with an accelerometer (acceleration sensor). That is, as disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-133375), when measuring hardness with an accelerometer, it is measured at the peak of the signal waveform at that time when it collides with an object.
JP 2001-133375 A

However, the hardness measurement method using such a conventional acceleration sensor has the following problems.
That is, as shown in FIG. 26, when a reference object made of rubber having different hardness is measured using such a conventional acceleration sensor, the peak value of the measured value is determined by the acceleration sensor. It depends on the strength of contact with an object. In FIG. 26, the rubber hardness 40, 50, 60 (JIS K6253, no unit) indicates a hard material in proportion to the number.

  Therefore, in the hardness measurement method using the conventional acceleration sensor, the conditions differ depending on the difference in strength with which the acceleration sensor contacts the object to be measured, the difference in contact angle, which causes a measurement error for each measurement, An accurate hardness measurement cannot be performed. Further, in the hardness measurement method using a conventional acceleration sensor, depending on the strength with which the acceleration sensor is brought into contact with the object to be measured, when measuring articles that are easily damaged or damaged, such as fruits and vegetables, The surface will be destroyed, the fruits and vegetables must be discarded, and the measurement efficiency will be reduced.

In view of such a current situation, the present invention provides a stable and accurate measurement without any measurement error for each measurement without different measurement conditions due to differences in contact strength and contact angle. Hardness measurement is possible, and even in the case of measuring easily damaged or damaged items such as fruits and vegetables, the surface of the fruits and vegetables can be measured without touching the product without touching the surface. An object of the present invention is to provide a hardness measuring apparatus for an article and a method for measuring the hardness of the article, which can measure the hardness of the article.

The present invention has been invented in order to achieve the above-described problems and objects in the prior art. The article hardness measurement apparatus of the present invention is an article hardness measurement apparatus for measuring the hardness of an article. And
A sensor member to be brought into contact with the article to be measured;
Two first sensors and two sensors having different sensitivities arranged on the sensor member with a sensitivity axis aligned;
The first sensor output by the first sensor and the second sensor output by the second sensor obtained by bringing the sensor member into contact with the object to be measured from the sensitivity direction of the two sensors. And by
A hardness identification control unit for identifying the hardness of the article to be measured;
It is characterized by providing.

The method for measuring the hardness of an article of the present invention is a method for measuring the hardness of an article for measuring the hardness of the article,
A sensor member to be brought into contact with the article to be measured;
Using a hardness measuring device for an article provided with two first sensors and two sensors having different sensitivities arranged on the sensor member with a sensitivity axis aligned,
The first sensor output by the first sensor and the second sensor output by the second sensor obtained by bringing the sensor member into contact with the object to be measured from the sensitivity direction of the two sensors. And determining the hardness of the article to be measured.

  By configuring in this way, the sensitivity axis is aligned with the sensor member, and the two first sensors and the second sensor having different sensitivities are arranged. Since there is no difference in strength, difference in angle, and measurement conditions are the same, the first sensor output from the first sensor and the second sensor output from the second sensor do not have different measurement conditions. There is no measurement error for each measurement, and stable and accurate hardness measurement is possible.

In the present invention, the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having different sensor capacities.
By configuring in this way, for example, in the acceleration sensor, the weight sensor, etc., the same type of sensor having different sensor capacities is used as the first sensor and the second sensor. Since the hardness is measured from the difference ratio, the measurement can be stably performed regardless of the strength and angle at which the sensor member abuts the article to be measured.

  Therefore, since the sensor member can be measured even if the strength with which the sensor member is brought into contact with the object to be measured is weakened to the extent that it is touched, even in the case of measuring easily damaged or damaged items such as fruits and vegetables, Accurate measurement of hardness is possible by abutting to the extent that the article is touched without destroying the surface. That is, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

  In the present invention, the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having the same sensor capacity and different response characteristics.

In this case, even if the sensor capacities of the first sensor and the second sensor are the same, the hardness is measured from the ratio of the difference in response characteristics by changing the response characteristics, for example, the response frequency of the sensors. Therefore, the measurement can be stably performed regardless of the strength and angle at which the sensor member comes into contact with the measurement object.

  In the present invention, the same type of sensors having different response characteristics may have a response characteristic of a sensor having a lower response characteristic in a range of 10 to 1000 hz, and a response characteristic of a higher sensor in a range of 1 to 10 Khz. It is characterized by.

  If the response frequency of the first sensor and the second sensor is within such a range, the hardness can be measured from the ratio of the difference in response characteristics, and the strength and angle at which the sensor member comes into contact with the object to be measured. Regardless of, it can be measured stably.

  As described above, as a method for making the response frequency of the first sensor different from that of the second sensor, a known method can be adopted, and is not particularly limited. In addition, a method for setting the response frequency of the first sensor and the second sensor to be different, a method for changing the response characteristic of the amplifier receiving the sensor, a filter by software, and the like can be used.

In the present invention, the two first sensors and the second sensor having different sensitivities are composed of sensors having different types of sensors.
With this configuration, for example, an acceleration sensor and a weight sensor are used as the first sensor and the second sensor, so that the hardness is measured from the ratio of the difference in response characteristics due to the difference in sensor type. The sensor member can be measured stably regardless of the strength and angle at which the sensor member comes into contact with the object to be measured.

  Therefore, since the sensor member can be measured even if the strength with which the sensor member is brought into contact with the object to be measured is weakened to the extent that it is touched, even in the case of measuring easily damaged or damaged items such as fruits and vegetables, Accurate measurement of hardness is possible by abutting to the extent that the article is touched without destroying the surface. That is, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

In the present invention, the sensor is an acceleration sensor or a weight sensor.
By configuring in this way,
(1) As the first sensor and the second sensor, both are acceleration sensors and have different sensor capacities.
(2) As the first sensor and the second sensor, both are weighted sensors with different sensor capacities,
(3) When an acceleration sensor and a weight sensor are used as the first sensor and the second sensor. (4) As the first sensor and the second sensor, both are the acceleration sensors and have the same sensor capacity and the response characteristics. If different
(5) When the first sensor and the second sensor are both weighted sensors with the same sensor capacity and different response characteristics,
In any of the cases, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

In addition to using such an acceleration sensor and a weight sensor, the speed may be measured by a speedometer. That is, the speed may be measured by integrating the acceleration sensor (adding the output from the acceleration sensor) and calculating from the pulse of the rotary encoder, for example.

  Further, in the hardness measurement apparatus for articles according to the present invention, the hardness identification control unit includes a ratio between a signal waveform of the first sensor output by the first sensor and a signal waveform of the second sensor output by the second sensor. By comparing the hardness of the article to be measured.

  Further, in the hardness measurement method for an article of the present invention, by comparing the ratio of the signal waveform of the first sensor output by the first sensor and the signal waveform of the second sensor output by the second sensor, It is characterized by identifying the hardness of the article to be measured.

  Thus, since the ratio of the signal waveform of the first sensor output by the first sensor and the signal waveform of the second sensor output by the second sensor is compared, the strength of the sensor member contacting the article to be measured Stable measurement is possible regardless of the angle.

  Therefore, since the sensor member can be measured even if the strength with which the sensor member is brought into contact with the object to be measured is weakened to the extent that it is touched, even in the case of measuring easily damaged or damaged items such as fruits and vegetables, Accurate measurement of hardness is possible by abutting to the extent that the article is touched without destroying the surface. That is, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

  In the hardness measuring apparatus for articles according to the present invention, the hardness identification control unit uses the first sensor output in the signal waveform of the first sensor output by the first sensor as the X axis and the second sensor by the second sensor. The hardness of the article to be measured is identified by performing an XY plot so that the second sensor output in the signal waveform of the sensor output is on the Y axis.

  In the article hardness measurement method of the present invention, the first sensor output signal waveform of the first sensor output by the first sensor is set to the X axis, and the second sensor output signal waveform of the second sensor is used. The hardness of the article to be measured is identified by plotting an XY plot so that the second sensor output at is on the Y axis.

  That is, the first sensor S1 and the second sensor S2 are calculated from the signal waveforms of the first sensor S1, the first sensor output of the first sensor S1 on the X axis, and the second sensor S2 of the second sensor S2 on the Y axis. The output is an XY plot.

  Thus, for example, when reference materials 40, 50, and 60 made of rubber having the same hardness as those used in FIG. 26 are measured, as shown in the graphs of FIGS. Features appear.

  In this case, in the graphs of FIGS. 6, 7, and 8, there are two waveforms each when the larger one (S 40, S 50, S 60) is in strong contact with the smaller one (W 40, W 50, W 60). Is a weak contact. As is clear from these graphs, it can be seen that the waveform of the soft reference object is more rounded. Therefore, if this feature is used for measuring the hardness, the hardness of the article to be measured can be measured.

  Further, in any of the graphs of FIGS. 6, 7, and 8, the area when weakly contacted (W40, W50, W60) is smaller than when strongly contacted (S40, S50, S60). It can be seen that is smaller but appears to be similar.

Therefore, if this graph is used, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.
In the article hardness measurement apparatus according to the present invention, the hardness identification control unit may measure the hardness of the article to be measured by using the X-axis value at 20% to 90% of the maximum value of the Y-axis as a hardness measurement index. It is comprised so that it may identify.

In the method for measuring the hardness of an article according to the present invention, the hardness of the article to be measured is identified using the value of the X axis in 20% to 90% of the maximum value of the Y axis as a measurement index of hardness. .
Thus, if the value of the X-axis at 20% to 90% of the maximum value of the Y-axis is used as the hardness measurement index, the correlation with the hardness is good, so that accurate hardness can be measured. .

  More specifically, an interval excluding the sensor output signal immediately after saturation and the last falling edge, for example, the value of the X axis in 20% to 90% of the maximum value of the Y axis is used as a measurement index of the hardness of the article to be measured. It is preferred to identify the hardness.

  In the hardness measuring apparatus for articles according to the present invention, the hardness identification control unit may use the second sensor at the peak of the first sensor output in the signal waveform of the first sensor output from the first sensor. The hardness of the article to be measured is identified by time-shifting the signal waveform of the second sensor output by the second sensor so that the output starts in the signal waveform of the second sensor output. It is characterized by that.

  In the hardness measurement method for an article of the present invention, the peak of the first sensor output in the signal waveform of the first sensor output by the first sensor is the second sensor output by the second sensor. The hardness of the article to be measured is identified by time-shifting the signal waveform of the second sensor output by the second sensor so that the output of the signal waveform starts.

  That is, for example, when reference materials 40, 50, 60, and 70 made of rubber having different hardness similar to those used in FIG. 26 are measured, the characteristics shown in the graph of FIG. 17 appear.

  In this case, as shown in the graph of FIG. 17, the first sensor output (signal waveform) by the first sensor S1 is 40x, 50x, 60x, and 70x, and the second sensor by the second sensor S2 The outputs (signal waveforms) are 40y, 50y, 60y, and 70y, and the time axes coincide with each other. Therefore, it is difficult to judge these peaks on, for example, a CRT (display device), and instantaneously. The hardness difference cannot be identified.

For this reason, as shown in the graph of FIG. 18, the first sensor S1 in the case where the sensor member is brought into contact with the hardest object to be measured, in this case, 70 reference objects, is used. At the time Txp at the peak 70xp of the signal waveform 70x of the sensor output, the output start point 70xp-0 of the signal waveform 70y of the second sensor output by the second sensor S2 starts at the time Txp. 2nd by the second sensor S2 to be located
All the signal waveforms of the sensor output S2 are time-shifted (see arrow A in FIG. 18).

  In this way, the first sensor output (signal waveform) by the first sensor S1 is 40x, 50x, 60x, and 70x, and the second sensor output (signal waveform) by the second sensor S2 is These peaks are 40y, 50y, 60y, and 70y, and it is easy to judge these peaks on, for example, a CRT (display device), and the difference in hardness can be identified instantaneously.

  Although such a time shift is not physically meaningful, the peak time of the first sensor output peak in the signal waveform of the first sensor output by the first sensor is By shifting the signal waveform of the second sensor output by the second sensor so as to be at the start of output in the signal waveform of the second sensor output by the second sensor, the analysis is facilitated, and the algorithm Easy to create.

  Moreover, in the hardness measuring apparatus for articles according to the present invention, the signal waveform of the second sensor output S2 by the second sensor S2 is all time-shifted in this way, and the hardness identification control unit is the first sensor by the first sensor. The XY plot is set so that the first sensor output in the signal waveform of the sensor output of 1 is on the X axis and the second sensor output in the signal waveform of the second sensor output by the second sensor is on the Y axis. By doing so, it is configured to identify the hardness of the article to be measured.

  In the method for measuring the hardness of an article of the present invention, the signal waveform of the second sensor output S2 by the second sensor S2 is all time-shifted in this way, and the signal of the first sensor output by the first sensor is also obtained. By measuring the XY plot so that the first sensor output in the waveform is on the X axis and the second sensor output in the signal waveform of the second sensor output by the second sensor is on the Y axis, It is characterized by identifying the hardness of the article.

That is, as shown in the graph of FIG. 18, the signal waveform of the second sensor output S2 by the second sensor S2 is all time-shifted so that the output start point 70xp-0 is located at the time Txp.

  In the graph of FIG. 18, the first sensor output 40x, 50x, 60x, 70x in the signal waveform of the first sensor output by the first sensor S1 is taken as the second axis by the second sensor S2 with the X axis as the X axis. When the second sensor outputs 40y, 50y, 60y, and 70y in the signal waveform of the sensor output are XY plotted so as to be on the Y axis, the graph of FIG. 19 is obtained. That is, a portion where the signal waveform of the first sensor output by the first sensor S1 changes sharply and a portion where the signal waveform of the second sensor output by the second sensor S2 changes gently are in the xy coordinates. It can be plotted (R40, R50, R60, R70 in FIG. 19).

  Accordingly, it is easy to make a determination on the CRT (display device) or the like from R40, R50, R60, and R70 in the graph of FIG. 19, and the difference in hardness can be identified instantaneously.

  Further, in the hardness measurement apparatus for an article according to the present invention, the hardness identification control unit has the XY-plotted graph having a substantially right triangle shape, and the inclination of the hypotenuse of the substantially right triangle causes the measurement object to be measured. It is characterized by being configured to identify the hardness.

  In the method for measuring the hardness of an article according to the present invention, the graph plotted in XY is a substantially right triangle, and the hardness of the article to be measured is identified by the inclination of the hypotenuse of the substantially right triangle. And

  That is, in the graph shown in FIG. 19, R40, R50, R60, and R70 are right triangles, and the hardness of the measurement article is determined by the hypotenuse of this substantially right triangle, the inclination of R40s, R50s, R60s, and R70s. Can be identified.

Moreover, in the hardness measuring apparatus for articles according to the present invention, the hardness identification control unit is substantially in the range of the Y-axis value that is smaller by a predetermined percentage from the vertex of the Y-axis of the substantially right triangle graph plotted in the XY manner. The hardness of the article to be measured is identified by the inclination of the hypotenuse of the right triangle.

  In the hardness measurement method for an article according to the present invention, the slope of the hypotenuse of the substantially right triangle in the range of the Y axis value that is smaller by a predetermined percentage from the vertex of the Y axis of the graph of the approximately right triangle plotted in the XY plot. The hardness of the article to be measured is identified.

  That is, in the graph shown in FIG. 20, R40, R50, R60, and R70 are right-angled triangles, and the hardness of the measurement article is determined by the hypotenuse of this substantially right-angled triangle and the inclination of R40s, R50s, R60s, and R70s. Identify.

  In this case, as shown in the graph of FIG. 20 (the reference object 70 is shown in the case of the graph of FIG. 20), a predetermined ratio from the vertex of the Y axis (90 in the case of the graph of FIG. 20). %), The hardness of the article to be measured may be identified by the inclination of the hypotenuse of the substantially right triangle within the range of the Y-axis value that is smaller by a percentage.

  If the slopes of the hypotenuses R40s, R50s, R60s, and R70s are within this range, the correlation with the hardness is good, and the accurate hardness can be measured. Note that this% of the slope measurement range of the hypotenuse varies depending on the response speed of the sensor.

  In the article hardness measurement apparatus according to the present invention, the hardness identification control unit may use the sensor member as an article to be measured so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. It is configured to perform a correction process using a force at the time of contact when the contact is made.

  In the article hardness measurement method of the present invention, the sensor member is brought into contact with the article to be measured so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. It is configured to perform a correction process by force at the time of contact.

  That is, in any of the graphs of FIGS. 6, 7, and 8, the area when the contact is weak (W40, W50, W60) as compared with the case where the contact is strong (S40, S50, S60). Although it appears smaller, it is similar.

Therefore, in the graphs of FIGS. 6, 7, and 8, the hardness can be identified by the hardness characteristics of these graphs by correcting (normalizing) the size.
That is, in such correction processing (standardization), if arithmetic processing is performed so that the maximum value of the second sensor output of the second sensor on the Y axis is 100, FIG. 9, FIG. 10, and FIG. In the graph of 11, the graphs of the case of strong contact (S40, S50, S60) and the case of weak contact (W40, W50, W60) almost coincide with each other. This process cancels the measurement, and the measurement can be performed stably regardless of the strength and angle at which the sensor member contacts the object to be measured.

In addition, such a process can be similarly corrected in the graphs shown in FIGS. 22 to 24 obtained by performing a time shift process and XY plotting (not shown).
Therefore, since the sensor member can be measured even if the strength with which the sensor member is brought into contact with the object to be measured is weakened to the extent that it is touched, even in the case of measuring easily damaged or damaged items such as fruits and vegetables, Accurate measurement of hardness is possible by abutting to the extent that the article is touched without destroying the surface. That is, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

  Further, in the article hardness measurement apparatus according to the present invention, the sensor member has a reference hardness having a predetermined reference hardness before the sensor member comes into contact with the object to be measured and measures the hardness of the object to be measured. It is configured to calibrate the hardness measurement data based on the hardness data of the reference hardness member in contact with the member.

  Further, in the method for measuring the hardness of an article according to the present invention, before the sensor member comes into contact with the article to be measured and measures the hardness of the article to be measured, the sensor member has a reference hardness having a predetermined reference hardness. The hardness measurement data is calibrated based on the hardness data of the reference hardness member in contact with the member.

  With this configuration, the sensor member abuts on a reference hardness member having a predetermined reference hardness and calibrates the hardness measurement data based on the hardness data of the reference hardness member. Variations due to changes over time such as temperature, humidity, and characteristics of the hardness measuring device itself can be corrected, and hardness measurement can be performed more accurately.

Moreover, the hardness measuring apparatus for an article of the present invention includes a temperature measuring apparatus for measuring the temperature of the reference hardness member,
Hardness measurement data is calibrated based on temperature data of a reference hardness member by the temperature measuring device.

  The method for measuring the hardness of an article according to the present invention is characterized in that the hardness measurement data is calibrated based on temperature data of the reference hardness member by a temperature measuring device that measures the temperature of the reference hardness member.

  Thus, based on the temperature data of the reference hardness member by the temperature measuring device that measures the temperature of the reference hardness member, since the hardness measurement data is calibrated, the temperature characteristics of the reference hardness member itself can be taken into account. For example, accurate hardness can be measured without being affected by ambient temperature such as indoors or farmlands.

  According to the present invention, the measurement conditions do not differ depending on the difference in contact strength and the contact angle with respect to the article, there is no measurement error for each measurement, and stable and accurate hardness measurement is possible. In addition, even when measuring articles that are easily damaged or damaged, such as fruits and vegetables, accurate hardness can be measured by touching the article without destroying the surface of the fruits and vegetables. Is possible.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
1 is a schematic front view of a hardness measuring apparatus for an article of the present invention, FIG. 2 is a schematic diagram in the I direction of the hardness measuring apparatus for the article of FIG. 1, FIG. 3 is an enlarged view of a sensor member, and FIG. It is the schematic which shows the use condition of the hardness measuring apparatus of the article | item of FIG.

In FIG. 1 to FIG. 3, reference numeral 10 denotes an overall hardness measuring apparatus for articles according to the present invention (hereinafter simply referred to as “hardness measuring apparatus”).
As shown in FIG. 1, the hardness measuring apparatus 10 includes a rotation shaft 12 that is supported by a shaft support mechanism (not shown), and an arm member 14 is attached to the rotation shaft 12. It is fixed so as to rotate as it rotates. The arm member 14 has a sensor member 16 attached to the tip thereof.

  The sensor member 16 is provided with a contact member 18 at a portion that comes into contact with the measurement object B such as fruits and vegetables. In addition, as shown in FIG. 4, a first sensor S <b> 1 is provided inside the sensor member 16 on the contact member 18 side, and a second sensor is arranged with the sensitivity axis aligned with the first sensor S <b> 1. The sensor S2 is arranged.

In this case, the first sensor S1 and the second sensor S2 are arranged on the contact surface 20 side of the contact member 18 so that the sensitivity direction is located.
On the other hand, a stepping motor 22 is mounted on the rotation shaft 12 as a rotation drive mechanism so as to rotate the rotation shaft 12, and an encoder 24 for detecting the rotation angle is provided on the opposite side. It is installed.

  Further, the first sensor S1, the second sensor S2, the stepping motor 22, and the encoder 24 are connected to a hardness identification control unit 26 that is a control mechanism for identifying the hardness of the article B to be measured such as a CPU. ing.

In this case, the first sensor S1 and the second sensor S2 are composed of two sensors having different sensitivities.
The two first sensors S1 and second sensors S2 having different sensitivities are preferably composed of the same type of sensors having different sensor capacities.

  That is, for example, in the acceleration sensor, the weight sensor, etc., the same kind of sensor having different sensor capacities is used as the first sensor S1 and the second sensor S2. Therefore, the measurement can be stably performed regardless of the strength and angle at which the sensor member 16 contacts the article to be measured B.

Moreover, it is preferable that the two first sensors S1 and the second sensor S2 having different sensitivities are composed of sensors having different types of sensors.
That is, as the first sensor S1 and the second sensor S2, for example, by using an acceleration sensor and a weight sensor, the hardness is measured from the ratio of the difference in response characteristics due to the difference in the type of sensor. Can be measured stably regardless of the strength and angle of contact with the article B to be measured.

  In addition, as the first sensor S1 and the second sensor S2, two first sensors S1 and second sensors S2 having different sensitivities are composed of the same type of sensors having the same sensor capacity and different response characteristics. May be.

  In this case, even if the sensor capacities of the first sensor S1 and the second sensor S2 are the same, by making the response characteristics, for example, the response frequency of the sensors different, the hardness is determined from the ratio of the difference in response characteristics. Therefore, the sensor member 16 can stably measure regardless of the strength and angle at which the sensor member 16 contacts the measurement object B.

  In this case, in the same type of sensors having different response characteristics, the response characteristic of the sensor having the lower response characteristic is in the range of 10 hz to 1000 hz, and the response characteristic of the higher sensor is in the range of 1 Khz to 10 Khz. It is desirable to set as follows.

  If the response frequency of the first sensor S1 and the second sensor S2 is within such a range, the hardness can be measured from the ratio of the difference in response characteristics, and the sensor member 16 can contact the article to be measured B. Stable measurement is possible regardless of the strength and angle of contact.

  Thus, as a method of making the response frequency of the first sensor S1 and the second sensor S2 different from each other, a known method can be adopted and is not particularly limited. A method of electrically setting the response frequency of the first sensor S1 and the second sensor S2 to be different, a method of changing the response characteristic of the amplifier receiving the sensor, a filter using software, and the like can be used.

Therefore, as a combination of two first sensors S1 and second sensors S2 having different sensitivities,
(1) As the first sensor and the second sensor, both are acceleration sensors and have different sensor capacities.
(2) As the first sensor and the second sensor, both are weighted sensors with different sensor capacities,
(3) When an acceleration sensor and a weight sensor are used as the first sensor and the second sensor. (4) As the first sensor and the second sensor, both are the acceleration sensors and have the same sensor capacity and the response characteristics. If different
(5) When the first sensor and the second sensor are both weighted sensors with the same sensor capacity and different response characteristics,
In any case, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness only by touching the article B to be measured, regardless of the force of contact.

  Accordingly, since the measurement can be performed even if the strength with which the sensor member 16 is brought into contact with the article B to be measured is weakened to the extent that it is touched, even in the case of measuring articles that are easily damaged or damaged, such as fruits and vegetables. Accurate measurement of hardness is possible by abutting to the extent that the article is touched without destroying the surface of the kind. That is, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness by simply touching the article to be measured regardless of the abutting force.

  In addition to using such an acceleration sensor and a weight sensor, the speed may be measured by a speedometer. That is, the speed may be measured by integrating the acceleration sensor (adding the output from the acceleration sensor) and calculating from the pulse of the rotary encoder, for example.

  As shown in FIG. 4, the hardness measuring apparatus 10 configured as described above is driven by the stepping motor 22 under the control of the hardness identification control unit 26, as indicated by the arrow in FIG. 4 from the initial position. By rotating the arm member 14 at a constant speed in a direction approaching the measurement object B, the contact surface 20 of the contact member 18 of the sensor member 16 at the tip thereof is in contact with the measurement object B. It has become.

  At the time of this contact, the hardness of the article to be measured B is identified by the first sensor output from the first sensor S1 disposed inside the sensor member 16 and the second sensor output from the second sensor S2. It is supposed to be.

  By configuring in this way, the first sensor S1 and the second sensor S2 having different sensitivities are arranged on the sensor member 16, so that the sensors S1 and S2 are covered. Since there is no difference in strength and angle, which is in contact with the measurement article B, and the measurement conditions are the same, the first sensor output by the first sensor S1 and the second sensor by the second sensor S2 As for the output, there is no measurement error for each measurement without different measurement conditions, and stable and accurate hardness measurement is possible.

Below, the identification method of such hardness is demonstrated.
(A) About hardness identification method without using time shift:
The following processing is automatically calculated in the hardness identification control unit 26, although not particularly mentioned below.

  In addition, the first sensor S1 and the second sensor S2 of this embodiment both use an acceleration sensor, and the first sensor S1 has a smaller sensor capacity, a faster response, and a second response. The sensor S2 has a larger sensor capacity and a slower response.

  First, when the contact surface 20 of the contact member 18 of the sensor member 16 contacts the measurement object B, the first sensor output (signal waveform W1) by the first sensor S1 and the second sensor The second sensor output (signal waveform W2) by S2 has a waveform as shown in FIG.

  In this case, since the sensor capacity of the first sensor S1 is smaller and the response is faster, the peak of the first sensor output (signal waveform W1) is earlier, and the sensor capacity of the second sensor S2 is larger. Since the response is slow, the peak of the second sensor output (signal waveform W2) is slow.

  In FIG. 5, the first sensor output (signal waveform W1) of the first sensor S1 by the first sensor S1 is taken as the X axis, and the second sensor output (signal waveform W2) by the second sensor S2 is taken as Y. An XY plot is made so that the axes are aligned.

  That is, the first sensor S1 and the second sensor S2 are calculated from the signal waveforms W1 and W2, and the first sensor output of the first sensor S1 is on the X axis, and the second sensor S2 is on the Y axis. XY plot the sensor output of 2.

  When such an XY plot is measured and carried out for reference materials 40, 50, 60 made of rubber having different hardness similar to that used in FIG. 26, for example, FIG. 6, FIG. 7, FIG. Features as shown in the graph of 8 appear.

  In this case, in the graphs of FIGS. 6, 7, and 8, there are two waveforms each when the larger one (S 40, S 50, S 60) is in strong contact with the smaller one (W 40, W 50, W 60). Is a weak contact.

  As is apparent from these graphs, it can be seen that the soft reference object (S40, W40 in the graph of FIG. 6) has a rounded waveform. Therefore, if this feature is used for measuring the hardness, the hardness of the article to be measured can be measured.

  Further, in any of the graphs of FIGS. 6, 7, and 8, the area when weakly contacted (W40, W50, W60) is smaller than when strongly contacted (S40, S50, S60). It can be seen that is smaller but appears to be similar.

Therefore, by using this graph, it is possible to provide a highly sensitive hardness sensor capable of measuring the hardness only by touching the article B to be measured, regardless of the force to be contacted.
In each of the graphs of FIGS. 6, 7, and 8, the area when weakly contacted (W40, W50, W60) is larger than when strongly contacted (S40, S50, S60). Although it appears smaller, it is similar.

Therefore, in the graphs of FIGS. 6, 7, and 8, the hardness can be identified by the hardness characteristics of these graphs by correcting (normalizing) the size.
That is, in such correction processing (standardization), if arithmetic processing is performed so that the maximum value of the second sensor output of the second sensor on the Y axis is 100, FIG. 9, FIG. 10, and FIG. In the graph of 11, the graphs of the case of strong contact (S40, S50, S60) and the case of weak contact (W40, W50, W60) almost coincide with each other. This process cancels the measurement, and the measurement can be performed stably regardless of the strength and angle at which the sensor member 16 contacts the measurement object B.

If these figures of FIGS. 9 to 11 are put together, a graph as shown in FIG. 12 is obtained.
In the graph of FIG. 12, the X-axis values (X40, X50, and X60 indicated by arrows) in the range of 20% to 90% of the maximum value of the Y-axis (ranges indicated by dotted lines and arrows C) are expressed as hardness. When used as a measurement index, as shown in the graph of FIG. 13, since the correlation with hardness is good (correlation coefficient 0.986), accurate hardness can be measured.

  More specifically, as indicated by an arrow C in FIG. 12, the value of the X axis in the interval excluding the saturation of the sensor output signal and the end of the falling edge, for example, 20% to 90% of the maximum value of the Y axis. It is preferable to identify the hardness of the article to be measured as a hardness measurement index.

  Also, in this case, if the hardness is identified as follows, the waveform will be slightly deviated at every measurement due to the effects of hysteresis remaining in the sensor and the external environment such as temperature. However, accurate hardness measurement is possible.

  That is, as shown in FIG. 14, in each graph (G40, G50, G60), from the hardness analysis start reference points A40, A50, A60 of the predetermined Y-axis% (60% in FIG. 14) of the rising portion, The hardness analysis end reference points B40, B50, and B60 in% (100% in FIG. 14) in the vicinity of the maximum value of the Y axis that is the rising end point may be used.

  That is, as shown in FIG. 14, the average of the angles of the vector groups C40, C50, C60 from the hardness analysis start reference points A40, A50, A60 to any point from the hardness analysis end reference points B40, B50, B60. If the value and standard deviation are used, this corresponds to the hardness.

  If the hardness is identified by such a method, since the hardness analysis start reference points A40, A50, A60 exist on the respective waveforms, the influence of hysteresis remaining in the sensor and the influence of the external environment such as temperature. Even if the waveform is slightly deviated at each measurement, the hardness is not affected and accurate hardness identification can be performed.

  In this case, the hardness analysis start reference points A40, A50, and A60 are not particularly limited in% of the Y axis, but preferably 20 to 80%. As B40, B50, and B60, the% of the Y-axis is preferably 80% to 100%.

  In addition, the number of vectors sampled in the vector groups C40, C50, and C60 is not particularly limited. However, in order to accurately identify the hardness, preferably about 10 vectors are sampled. It is desirable to obtain the angle and standard deviation.

  Similarly to FIG. 14, as shown in FIG. 15, in each graph (G40, G50, G60), the hardness analysis start reference for% of the predetermined Y axis at the falling portion (80% in FIG. 15). Vector groups C40, C50, C60 from points D40, D50, D60 to hardness analysis end reference points E40, E50, E60 in% (20% in FIG. 15) in the vicinity of the minimum value of the Y-axis, which is the end point of falling, respectively. May be used.

In this case, the hardness analysis start reference points D40, D50, and D60 are not particularly limited as% of the Y axis, but preferably 90 to 60%. As E40, E50, and E60, it is desirable that the% of the Y axis is preferably 20% to 40%.

  In FIG. 15, only the graph G60 is shown, but from the vector group along the curve of the graph G60, that is, from the hardness analysis start reference points D40, D50, and D60, the minimum value of the Y axis that is the falling end point Vector groups up to hardness analysis end reference points E40, E50, and E60 in nearby% (20% in FIG. 15) may be used.

  In the embodiment of FIG. 5A, in the case of FIG. 5, the first sensor S1 and the second sensor S2 both show the case where acceleration sensors having different sensor capacities are used. 6 to 16 show a case where an acceleration sensor is used as the first sensor S1 and a weight sensor is used as the second sensor S2.

  However, the first sensor S1 and the second sensor S2 both use acceleration sensors with different sensor capacities, use weight sensors with different sensor capacities, and use acceleration sensors and weight sensors. In either case, the hardness can be measured basically by the same principle.

  In addition to using such an acceleration sensor and a weight sensor, the speed may be measured by a speedometer. That is, the speed may be measured by integrating the acceleration sensor (adding the output from the acceleration sensor) and calculating from the pulse of the rotary encoder, for example.

For example, FIG. 16 shows a graph in which the first sensor S1 and the second sensor S2 are XY plotted when the response speeds of the two sensors are close. In this case, The width E (E1, E2) of the line D (D1, D2) perpendicular to the inclination line C of the graph may be used as an index for identifying hardness.

(B) Hardness identification method using time shift (when using the same type of sensor with different sensor capacities):
Hereinafter, the hardness measurement using the time shift of the embodiment different from the above-described hardness measurement method will be described.

  Note that both the first sensor S1 and the second sensor S2 of this embodiment use an acceleration sensor, and the first sensor S1 has a smaller sensor capacity, a faster response, and a second response. The sensor S2 has a larger sensor capacity and a slower response.

  In the hardness measurement method of this embodiment, for example, when a reference material 40, 50, 60, 70 made of rubber having different hardness similar to that used in FIG. 26 is measured, it is shown in the graph of FIG. Such features appear.

  In this case, as shown in the graph of FIG. 17, the first sensor output (signal waveform) by the first sensor S1 is 40x, 50x, 60x, and 70x, and the second sensor by the second sensor S2 The outputs (signal waveforms) are 40y, 50y, 60y, and 70y, and the time axes coincide with each other. Therefore, it is difficult to judge these peaks on, for example, a CRT (display device), and instantaneously. The hardness difference cannot be identified.

For this reason, as shown in the graph of FIG. 18, the first sensor S1 in the case where the sensor member is brought into contact with the hardest object to be measured, in this case, 70 reference objects, is used. At the time Txp at the peak 70xp of the signal waveform 70x of the sensor output, the output start point 70xp-0 of the signal waveform 70y of the second sensor output by the second sensor S2 starts at the time Txp. 2nd by the second sensor S2 to be located
All the signal waveforms of the sensor output S2 are time-shifted (see arrow A in FIG. 18).

  In this way, the first sensor output (signal waveform) by the first sensor S1 is 40x, 50x, 60x, and 70x, and the second sensor output (signal waveform) by the second sensor S2 is These peaks are 40y, 50y, 60y, and 70y, and it is easy to judge these peaks on, for example, a CRT (display device), and the difference in hardness can be identified instantaneously.

  Further, in the graph of FIG. 18, the second sensor S2 outputs the second sensor S2 with the first sensor outputs 40x, 50x, 60x, and 70x in the signal waveform of the first sensor output by the first sensor S1 as the X axis. When the second sensor outputs 40y, 50y, 60y, and 70y in the signal waveform of the sensor output are XY plotted so as to be on the Y axis, the graph of FIG. 19 is obtained. That is, a portion where the signal waveform of the first sensor output by the first sensor S1 changes sharply and a portion where the signal waveform of the second sensor output by the second sensor S2 changes gently are in the xy coordinates. It can be plotted (R40, R50, R60, R70 in FIG. 19).

  Accordingly, it is easy to make a determination on the CRT (display device) or the like from R40, R50, R60, and R70 in the graph of FIG. 19, and the difference in hardness can be identified instantaneously.

  That is, in the case of R70, the time T0 in FIG. 18 corresponds to the time T0 because the output of the first sensor and the output of the second sensor are 0 in FIG. . In FIG. 18, since the first sensor output is the maximum value at 70xp and the second sensor output is 0 at the location of time Txp, the Rxp point (substantially triangular vertex) in FIG. ).

  Further, in FIG. 18, the point at time T1 corresponds to the point R1 in FIG. 19, and is located on the hypotenuse of a substantially triangle. In FIG. 18, at time T2, the output of the first sensor is 0, and the second sensor output is 70 × 2, which is the maximum value. Therefore, in FIG. Corresponds to the vertex).

  As time elapses, the first sensor output remains 0, and the second sensor output decreases as indicated by R in FIG. 18, so that it returns to the R0 point in FIG. become.

  In the graph shown in FIG. 19, R40, R50, R60, and R70 are right triangles, and the hardness of the measurement article is identified by the hypotenuse of the substantially right triangle and the slopes of R40s, R50s, R60s, and R70s. be able to.

  In this case, as shown in the graph of FIG. 20 (the reference object 70 is shown in the case of the graph of FIG. 20), a predetermined ratio from the vertex of the Y axis (90 in the case of the graph of FIG. 20). The hardness of the article to be measured may be identified by the slope of the hypotenuse of a substantially right triangle within the range of the Y-axis value that is small by the percentage of the hypotenuse at the point P1.

If the slopes of the hypotenuses R40s, R50s, R60s, and R70s are within this range, the correlation with the hardness is good, and the accurate hardness can be measured.
Note that the percentage of the slope measurement range of this hypotenuse varies depending on the response speed of the sensor, but considering the correlation, it is preferably 95% to 50%, more preferably from the top of the Y axis. It is desirable to identify the hardness of the article to be measured by the inclination of the hypotenuse of a substantially right triangle in the range of the Y-axis value that is 95% to 85% smaller.

  Further, although not shown, in this case as well, the correction process (standardization) is strongly applied if an arithmetic process is performed so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. The graph in the case of contact and the case of weak contact will almost coincide, so that the strength of the force is canceled by this processing, and the strength at which the sensor member contacts the object to be measured Stable measurement is possible regardless of the angle.

  In the embodiment shown in FIG. 17B, in the case of FIGS. 17 to 21, the first sensor S1 and the second sensor S2 are both acceleration sensors having different sensor capacities. Yes.

  However, the hardness of the first sensor S1 and the second sensor S2 can be measured basically by the same principle even when weighted sensors having different sensor capacities are used.

  Although the time width A is the time width A, the time width A is not particularly limited, and the above-mentioned condition is necessary to make the XY plotted graph after the time shift into a substantially triangular shape. However, the smaller the time width, the more the XY plotted graph changes from a substantially triangular shape to the graph shown in FIG. Therefore, an appropriate time width suitable for hardness identification may be set in such a change.

Although such a time shift is not physically meaningful, the peak time of the first sensor output peak in the signal waveform of the first sensor output by the first sensor is By shifting the signal waveform of the second sensor output by the second sensor so as to be at the start of output in the signal waveform of the second sensor output by the second sensor, the analysis is facilitated, and the algorithm Easy to create.
(C) About hardness identification method using time shift (when using different sensor types):
In this embodiment, the first sensor S1 uses an acceleration sensor, and the second sensor S2 uses a weighted sensor. The first sensor S1 has a smaller sensor capacity, a faster response, and a second sensor. The sensor S2 has a larger sensor capacity and a slower response.

Also in this case, the time-shifted graph is the graph of FIG. 21 as in the graph of FIG. 18 of the above embodiment (B).
The graph obtained by XY plotting the graph of FIG. 21 in the same manner as the graph of FIG. 19 of Example (B) is shown in FIG. 22 (reference object 40), FIG. 23 (reference object 50), and FIG. It is a graph of the reference | standard thing 60).

In addition, in these cases of FIGS. 22 to 24, both graphs of the case of strong and strong contact and the case of weak contact are shown.
Also in this case, as shown in FIG. 25, the hardness can be identified by the inclination of the hypotenuse of a substantially right triangle, and a predetermined ratio from the top of the Y axis (in the case of the graph of FIG. 25, the reference object of FIG. If the hardness of the object to be measured is identified by the slope of the hypotenuse of the substantially right triangle in the range of the Y-axis value that is smaller by the inclination of the hypotenuse at the point P1 of 90%, the correlation with the hardness is shown. Is good, and it is possible to measure an accurate hardness.

  Further, although not shown, in this case as well, the correction process (standardization) is strongly applied if an arithmetic process is performed so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. The graph in the case of contact and the case of weak contact will almost coincide, so that the strength of the force is canceled by this processing, and the strength at which the sensor member contacts the object to be measured Stable measurement is possible regardless of the angle.

In the embodiment of (C), in FIGS. 21 to 25, the first sensor S1 uses an acceleration sensor, and the second sensor S2 uses a weight sensor, but conversely, the first sensor S1. Can be a weighted sensor, and the second sensor S2 can be an acceleration sensor.
(D) Hardness identification method using time shift (when using the same type of sensor with the same sensor capacity and different response characteristics):
In this embodiment, the first sensor S1 and the second sensor S2 use acceleration sensors having the same capacitance. Further, even if the sensor capacities of the first sensor S1 and the second sensor S2 are the same, the response frequency of the sensor is made different as response characteristics.

  Specifically, the response characteristics of the amplifier received by the first sensor S1 and the second sensor S2 are measured as the measurement conditions. As described below, for the first sensor S1, an amplifier having a fast response characteristic, For the second sensor S2, an amplifier having a slow response characteristic is used.

That is, as an amplifier
First sensor S1: “WGA-100” (manufactured by Kyowa Denki Co., Ltd.), (response characteristic 200HZ),
Second sensor S2: “WGA-100” (manufactured by Kyowa Denki Co., Ltd.), (response characteristic 1KHZ),
Is used.

Thereby, the response of the first sensor S1 is faster, and the response of the second sensor S2 is slower.
Also in this case, although not shown, the time shift is performed as in the graph of FIG.

  The graph obtained by XY plotting of the time-shifted graph in the same manner as the graph of FIG. 19 of the above-described Example (B) is shown in FIG. 27 (reference object 40), FIG. 28 (reference object 50), FIG. 29 (reference object 60).

Note that, in these cases of FIGS. 27 to 29, both graphs of the case of strong contact and the case of weak contact are shown.
Also in this case, similarly to the graph of FIG. 25 of the above-described embodiment (B), the hardness can be identified by the inclination of the hypotenuse of the substantially right triangle, and the range of the Y-axis value that is smaller by a predetermined percentage from the vertex of the Y-axis. If the hardness of the article to be measured is identified by the inclination of the hypotenuse of the substantially right-angled triangle, the correlation with the hardness is good, and the accurate hardness can be measured.

  Further, as shown in the graphs of FIG. 30 (reference object 40), FIG. 31 (reference object 50), and FIG. 32 (reference object 60), also in this case, correction processing (normalization) is performed on the Y axis. If the calculation process is performed so that the maximum value of the second sensor output of the second sensor S2 is 100, the graph when the contact is strong and the contact when the contact is weak is almost the same. As a result, the strength of the force is canceled by this process, and the sensor member can be stably measured regardless of the strength and angle at which the sensor member abuts the article to be measured.

In this case, as shown in the graph of FIG. 33, the correlation with the hardness is good (because the correlation coefficient is 0.91, accurate hardness can be measured. In this case, the capacity Although the correlation coefficient is slightly lower than that of sensors having different values, even in this case, sufficiently accurate hardness can be measured practically.
(E) About a hardness identification method using calibration of hardness measurement data by a reference hardness member:
In the hardness measuring apparatus 10 of this embodiment, the sensor member 16 has a predetermined reference hardness before the sensor member 16 comes into contact with the measured object B and measures the hardness of the measured article B. It is configured to calibrate the hardness measurement data based on the hardness data of the reference hardness member in contact with the member (built-in reference member).

  By configuring in this way, the sensor member 16 abuts on a reference hardness member having a predetermined reference hardness and calibrates the hardness measurement data based on the hardness data of the reference hardness member. Variations due to changes over time such as environmental temperature, humidity, and the characteristics of the hardness measuring device itself can be corrected, and hardness measurement can be performed more accurately.

  That is, hereinafter, as an example of a factor that affects the measurement by the hardness measuring apparatus 10, a case where the hardness measurement data is calibrated by the ambient environmental temperature (specifically, the temperature of the measurement chamber) will be described.

  As shown in FIG. 34, when the same reference hardness member is measured, the hardness measurement value of the reference hardness member changes due to a change in ambient environmental temperature. Further, as shown in FIG. 35, when the same sample (measurement article B) is measured, the hardness measurement value of the sample changes due to a change in the ambient environmental temperature.

  Therefore, the hardness measurement value data of the sample shown in FIG. 35 is calibrated with the hardness measurement value data of the reference hardness member shown in FIG. 34 (specifically, the hardness measurement value of the reference hardness member is calculated from the sample hardness measurement data value). If the data is subtracted), as shown in FIG. 36, it is understood that almost the same hardness measurement value of the same sample (measured article B) can be obtained without being affected by the temperature. .

  Therefore, for the reference hardness members 1 to 4, as shown in FIG. 37, the hardness measurement value data of the reference hardness member corresponding to the ambient environmental temperature is obtained, and as shown in FIG. Samples 1 to 4 (measurement article B) corresponding to the temperature are measured.

39, the samples 1 to 4 (measured article B) hardness measurement value data shown in FIG. 38 are calibrated with the hardness measurement value data of the reference hardness members 1 to 4 shown in FIG. Specifically, if the hardness measurement value data of the reference hardness member is subtracted from the sample hardness measurement data value), it is substantially the same for the same sample (measured article B) without being affected by temperature. It can be seen that a sample hardness measurement is obtained.

  Thus, before the sensor member 16 comes into contact with the article to be measured B and measures the hardness of the article to be measured B, the sensor member 16 becomes a reference hardness member (built-in reference member) having a predetermined reference hardness. By simply abutting and calibrating the hardness measurement data based on the hardness data of the reference hardness member, for example, it is possible to correct variations due to changes over time, such as the ambient temperature, humidity, and characteristics of the hardness measurement device itself. It is possible to measure the hardness more accurately.

In the above embodiment, data measured for a reference object having a standard hardness is accumulated in the storage unit of the hardness identification control unit 26 in advance, and these data are compared with measurement data of the article B actually measured. By doing so, the hardness can be identified instantly.

Each graph and hardness data can be displayed and printed on a display device such as a CRT.
In the above-described embodiment, the arm member 14 is rotated by the stepping motor 22 so that the contact surface 20 of the contact member 18 of the sensor member 16 at the tip of the arm member 14 contacts the article B to be measured. . However, in place of the stepping motor 22, other drive mechanisms such as a piston cylinder mechanism and a spring member can be employed. Furthermore, it is also possible to make it contact manually.

  Although not shown, a temperature measuring device for measuring the temperature of the reference hardness member may be provided, and the hardness measurement data may be calibrated based on the temperature data of the reference hardness member by the temperature measuring device.

  In this way, if the hardness measurement data is calibrated based on the temperature data of the reference hardness member by the temperature measuring device that measures the temperature of the reference hardness member, the temperature characteristics of the reference hardness member itself can be taken into account. For example, accurate hardness can be measured without being affected by ambient temperature such as indoors or farmlands.

Furthermore, if the temperature of the reference hardness member is adjusted to 30 ° C. ± 5 degrees with a rubber heater, the reference hardness does not change depending on the temperature, so that accurate measurement can be performed.
The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. For example, in the above embodiment, the article to be measured B is applied to fruits and vegetables such as fruits and vegetables. However, various modifications can be made without departing from the object of the present invention, such as being applicable to measuring the hardness of other articles such as electronic parts.

FIG. 1 is a schematic front view of a hardness measuring apparatus for articles according to the present invention. FIG. 2 is a schematic diagram in the I direction of the hardness measuring apparatus for the article of FIG. FIG. 3 is an enlarged view of the sensor member. FIG. 4 is a schematic view showing a use state of the hardness measuring apparatus for the article of FIG. FIG. 5 shows a first sensor output (signal waveform W1) by the first sensor S1 and a second sensor output (signal waveform W2) by the second sensor S2 when the product B comes into contact with the measurement object B. It is a graph to show. FIG. 6 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 7 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 8 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 9 is a graph obtained by correcting (normalizing) the graph of FIG. 6 so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 10 is a graph obtained by correcting (normalizing) the graph of FIG. 7 so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 11 is a graph obtained by correcting (normalizing) the graph of FIG. 8 so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 12 is a graph summarizing the diagrams of FIGS. FIG. 13 is a graph showing the correlation with the hardness when the value of the X axis in the range of 40% of the maximum value of the Y axis of the graph of FIG. 12 is used as a hardness measurement index. FIG. 14 is a graph in which correction processing (normalization) is performed so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 15 is a graph in which correction processing (normalization) is performed so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 16 is an XY plot graph in the case of using an acceleration sensor and an acceleration sensor. FIG. 17 is a graph showing a first sensor output by the first sensor S1 and a second sensor output by the second sensor S2 when the product B comes into contact with the measurement object B. FIG. 18 is a graph obtained by time-shifting all signal waveforms of the second sensor output S2 by the second sensor S2. FIG. 19 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 20 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 21 is a time-shifted graph similar to the graph of FIG. FIG. 22 is an XY plotted graph similar to the graph of FIG. FIG. 23 is an XY plotted graph similar to the graph of FIG. FIG. 24 is an XY plotted graph similar to the graph of FIG. FIG. 25 is an X-Y plotted graph for explaining the identification of hardness in the graph of FIG. FIG. 26 is a graph showing the correlation between the sun output and the hardness when only one conventional acceleration sensor is used. FIG. 27 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 28 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 29 is a graph obtained by XY plotting the first sensor output of the first sensor S1 on the X axis and the second sensor output of the second sensor S2 on the Y axis. FIG. 30 is a graph obtained by correcting (normalizing) the graph of FIG. 27 so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 31 is a graph obtained by correcting (normalizing) the graph of FIG. 28 so that the maximum value of the second sensor output of the second sensor on the Y axis becomes 100. FIG. 32 is a graph obtained by correcting (normalizing) the graph of FIG. 29 so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. FIG. 33 is a graph showing the correlation with hardness when the value of the X axis in the range of 40% of the maximum value of the Y axis of the graphs of FIGS. 30 to 32 is used as a hardness measurement index. FIG. 34 is a graph showing the relationship between the ambient environmental temperature and the measured hardness value of the reference hardness member when the same reference hardness member is measured. FIG. 35 is a graph showing the relationship between the ambient environmental temperature and the measured hardness value of the sample when the same sample (measurement article B) is measured. 36 shows the relationship between the ambient environmental temperature and the sample hardness measurement value when the sample hardness measurement value data shown in FIG. 35 is calibrated with the hardness measurement value data of the reference hardness member shown in FIG. It is a graph. FIG. 37 is a graph showing the relationship between the ambient environmental temperature and the measured hardness value of the reference hardness member for the reference hardness members 1 to 4. FIG. 38 is a graph showing the relationship between the ambient environmental temperature and the sample hardness measurement value for Samples 1 to 4 (measurement article B). FIG. 39 shows the relationship between the ambient environmental temperature and the sample hardness measurement value when the sample hardness measurement value data shown in FIG. 38 is calibrated with the hardness measurement value data of the reference hardness member shown in FIG. It is a graph.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hardness measuring apparatus 12 Rotating shaft 14 Arm member 16 Sensor member 18 Contact member 20 Contact surface 22 Stepping motor 24 Encoder 26 Hardness identification control part

Claims (32)

An article hardness measuring apparatus for measuring the hardness of an article,
A sensor member to be brought into contact with the article to be measured;
Two first sensors and two sensors having different sensitivities arranged on the sensor member with a sensitivity axis aligned;
The first sensor output by the first sensor and the second sensor output by the second sensor obtained by bringing the sensor member into contact with the object to be measured from the sensitivity direction of the two sensors. Depending on the ratio of the difference in response characteristics with
A hardness identification control unit for identifying the hardness of the article to be measured;
An apparatus for measuring the hardness of an article.   The apparatus for measuring hardness of an article according to claim 1, wherein the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having different sensor capacities.   The hardness of the article according to claim 1, wherein the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having the same sensor capacity and different response characteristics. measuring device.   The same type of sensors having different response characteristics are characterized in that the response characteristic of the sensor having the lower response characteristic is in the range of 10 to 1000 hz, and the response characteristic of the higher sensor is in the range of 1 to 10 Khz. The apparatus for measuring hardness of an article according to 3.   2. The article hardness measurement apparatus according to claim 1, wherein the two first sensors and the second sensor having different sensitivities are configured by sensors having different types of sensors.   The apparatus for measuring the hardness of an article according to any one of claims 2 to 5, wherein the sensor is an acceleration sensor or a weight sensor.   The hardness identification control unit compares the ratio of the signal waveform of the first sensor output from the first sensor with the signal waveform of the second sensor output from the second sensor, thereby determining the hardness of the article to be measured. The apparatus for measuring hardness of an article according to any one of claims 1 to 6, wherein the apparatus is configured to identify the article.   The hardness identification control unit uses the first sensor output in the signal waveform of the first sensor output by the first sensor as the X axis, and the second sensor output in the signal waveform of the second sensor output by the second sensor. The apparatus for measuring the hardness of an article according to claim 7, wherein the hardness of the article to be measured is identified by performing an XY plot so as to be on the Y axis.   The hardness identification control unit is configured to identify the hardness of an article to be measured using the value of the X axis in 20% to 90% of the maximum value of the Y axis as a measurement index of hardness. The apparatus for measuring hardness of an article according to claim 8.   When the hardness identification control unit starts output in the signal waveform of the second sensor output by the second sensor when the peak of the first sensor output in the signal waveform of the first sensor output by the first sensor starts. The article according to claim 7, wherein the hardness of the article to be measured is identified by time-shifting the signal waveform of the second sensor output by the second sensor. Hardness measuring device.   The hardness identification control unit uses the first sensor output in the signal waveform of the first sensor output by the first sensor as the X axis, and the second sensor output in the signal waveform of the second sensor output by the second sensor. The apparatus for measuring hardness of an article according to claim 10, wherein the hardness of the article to be measured is identified by performing an XY plot so as to be on the Y axis.   The hardness identification control unit is configured such that the XY plotted graph has a substantially right triangle shape, and the hardness of the article to be measured is identified by the inclination of the hypotenuse of the substantially right triangle. The apparatus for measuring the hardness of an article according to claim 11.   The hardness identification control unit determines the slope of the hypotenuse of the substantially right triangle in the range of the Y axis value that is smaller by a predetermined ratio from the vertex of the Y axis of the graph of the substantially right triangle plotted in XY. The apparatus for measuring hardness of an article according to claim 12, wherein the apparatus is configured to identify hardness.   At the time of contact when the hardness identification control unit causes the sensor member to contact the object to be measured so that the maximum value of the second sensor output of the second sensor on the Y axis is 100. The apparatus for measuring hardness of an article according to any one of claims 8, 9, and 11 to 13, wherein the apparatus is configured to perform correction processing using force.   Before the sensor member comes into contact with the measured article and measures the hardness of the measured article, the sensor member comes into contact with a reference hardness member having a predetermined reference hardness, and the hardness of the reference hardness member The apparatus for measuring hardness of an article according to any one of claims 1 to 14, wherein the apparatus is configured to calibrate hardness measurement data based on the data. A temperature measuring device for measuring the temperature of the reference hardness member;
The apparatus for measuring hardness of an article according to any one of claims 1 to 15, wherein the apparatus is configured to calibrate hardness measurement data based on temperature data of a reference hardness member by the temperature measuring device. A method for measuring the hardness of an article for measuring the hardness of the article, comprising:
A sensor member to be brought into contact with the article to be measured;
Using a hardness measuring device for an article provided with two first sensors and two sensors having different sensitivities arranged on the sensor member with a sensitivity axis aligned,
The first sensor output by the first sensor and the second sensor output by the second sensor obtained by bringing the sensor member into contact with the object to be measured from the sensitivity direction of the two sensors. A hardness measurement method for an article, wherein the hardness of the article to be measured is identified by a ratio of a difference in response characteristics with respect to the measurement object.   18. The method for measuring hardness of an article according to claim 17, wherein the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having different sensor capacities.   18. The hardness of the article according to claim 17, wherein the two first sensors and the second sensor having different sensitivities are composed of the same type of sensors having the same sensor capacity and different response characteristics. Measuring method.   The same type of sensors having different response characteristics are characterized in that the response characteristic of the sensor having the lower response characteristic is in the range of 10 to 1000 hz, and the response characteristic of the higher sensor is in the range of 1 to 10 Khz. 20. A method for measuring the hardness of an article according to item 19.   18. The method for measuring hardness of an article according to claim 17, wherein the two first sensors and the second sensor having different sensitivities are composed of sensors having different types of sensors.   The method according to claim 18, wherein the sensor is an acceleration sensor or a weight sensor.   The hardness of the article to be measured is identified by comparing the ratio of the signal waveform of the first sensor output from the first sensor and the signal waveform of the second sensor output from the second sensor. The method for measuring the hardness of an article according to any one of claims 17 to 22.   The first sensor output in the signal waveform of the first sensor output by the first sensor is on the X axis, and the second sensor output in the signal waveform of the second sensor output by the second sensor is on the Y axis. 24. The method for measuring the hardness of an article according to claim 23, wherein the hardness of the article to be measured is identified by performing an XY plot.   25. The method for measuring the hardness of an article according to claim 24, wherein the hardness of the article to be measured is identified using the value of the X axis in a range from 20% to 90% of the maximum value of the Y axis as a measurement index of hardness.   The second time is such that the peak of the peak of the first sensor output in the signal waveform of the first sensor output by the first sensor is the output start time in the signal waveform of the second sensor output by the second sensor. 24. The method of measuring hardness of an article according to claim 23, wherein the hardness of the article to be measured is identified by time-shifting the signal waveform of the second sensor output by the sensor.   The first sensor output in the signal waveform of the first sensor output by the first sensor is on the X axis, and the second sensor output in the signal waveform of the second sensor output by the second sensor is on the Y axis. 27. The method of measuring hardness of an article according to claim 26, wherein the hardness of the article to be measured is identified by performing an XY plot.   28. The hardness measurement of an article according to claim 27, wherein the XY plotted graph has a substantially right triangle shape, and the hardness of the article to be measured is identified by a slope of a hypotenuse of the substantially right triangle. Method.   The hardness of the article to be measured is identified by the slope of the hypotenuse of the substantially right triangle in the range of the Y axis value that is smaller by a predetermined percentage from the vertex of the Y axis of the graph of the substantially right triangle plotted in the XY plot. The method for measuring the hardness of an article according to claim 28.   Correction processing is performed by force at the time of contact when the sensor member is brought into contact with the article to be measured so that the maximum value of the second sensor output of the second sensor on the Y-axis becomes 100. 30. The method for measuring the hardness of an article according to any one of claims 24, 25 and 27 to 29, wherein the article is configured as described above.   Before the sensor member comes into contact with the article to be measured and measures the hardness of the article to be measured, the sensor member is brought into contact with a reference hardness member having a predetermined reference hardness, The method for measuring the hardness of an article according to any one of claims 17 to 30, wherein the hardness measurement data is calibrated based on the hardness data.   The hardness measurement of an article according to any one of claims 17 to 31, wherein the hardness measurement data is calibrated based on temperature data of the reference hardness member by a temperature measuring device that measures the temperature of the reference hardness member. Method.

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