JP2002236049A - Counting scale - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a counting scale which properly secure response speed and weighing accuracy, regardless of the weight of articles to be counted. SOLUTION: This counting scale is equipped with a stability decision part 24, which inputs a weighting signal generated by detecting the weight of articles to be counted and decides whether the weighing signal becomes temporally stable and a decision control part 40, which changes stability decision conditions of the stability decision part 24, according to a unit weight M of the articles. When the unit weight M is relatively large, the decision control part 40 expands the decision conditions of the stability decision part 24, to increase the temporal reflection speed of the reflection of variation of the weighing signal on the input of the stability decision part 24. Conversely, when the unit weight M is relatively small, decision conditions are made narrow to lower the temporal reflection speed. Consequently, when the unit price of the articles to be counted is relatively large, the response speed increases, an when it is relatively small, the weighting accuracy is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counting scale for weighing a set of articles and counting the number of articles included in the set.

[0002]

2. Description of the Related Art In general, a weighing signal obtained by detecting the total weight of a large number of articles on a counting scale includes various vibrations such as vibration at the time of placing the articles to be weighed and vibrations caused by the installation environment such as wind and floor vibration. Noise is included.

For this reason, it is determined that the detected weighing signal has been stabilized when the high-frequency component of the vibration noise is removed by a low-pass filter and the temporal fluctuation width of the weighing signal becomes smaller than a predetermined stabilization width. The final weighed value. By this processing, even if various weighing noises are included in the weighing signal, it is possible to obtain a weighing value in which the influence thereof is reduced. In the counting scale, the number of articles is counted by dividing the final weighed value by the weight per article (hereinafter, “single weight”).

Here, in the process of determining that the weighing signal is "stable", the weighing signal is converted into weighing data for discrimination, and the time chain of the weighing data for discrimination satisfies a predetermined condition. To determine if they are Then, a determination parameter that defines a processing process for determining “stable” is set in advance.

The discrimination parameters for such stabilization discrimination include (1) discrimination conditions to be satisfied for discriminating that the weighing signal is stable (hereinafter, simply referred to as “stability discrimination conditions”).
And (2) converting the input weighing signal into weighing data used in actual stabilization determination.
There are two types, a temporal reflection speed (hereinafter, simply referred to as “temporal reflection speed”) that defines how much the temporal change of the weighing signal is reflected in the weighing data.

Here, if the value of the discrimination parameter is set with priority on the weighing accuracy, it takes time to finally determine that "stabilized", while priority is given to the response speed. If the value of the discrimination parameter is set so that the final measured value is determined early, there is a conflicting property that the measured value is determined before actually stabilizing.

For this reason, in the conventional counting scale, the optimum value of the discrimination parameter is previously determined to be one in consideration of the balance between the weighing accuracy and the response speed.
It is configured to weigh various articles based on the optimum value.

[0008]

However, when weighing a set of articles having a relatively large unit weight, the dynamics at the stage of sequentially feeding the set of articles onto a counting scale are measured. Because the vibrations tend to be large, the weighing value oscillates with a large amplitude for a relatively long time even after the last one of the articles has been fed on the counting scale. For this reason, with the value of the discrimination parameter set assuming an average single-weight article, it takes a long time until it is determined that the article is stabilized, and the response time tends to be long.

Conversely, for articles having a relatively small unit weight,
The time change of the total weight at the stage of sequentially supplying the set on the counting scale is relatively slow,
In addition, since the mechanical vibration is small, it is determined that the last one of the articles has stabilized before being supplied onto the counting scale, and the weighing accuracy tends to decrease.

[0010] These properties will be described more specifically in the section of "Principle of the Invention" which will be described later. However, in a conventional counting scale, fixed values are used as these discrimination parameters, and it is necessary to measure them. There has been a problem that the bias of any one of the response speed and the weighing accuracy easily occurs due to the single weight of the article.

The present invention has been made in view of the above problems, and has as its object to provide a counting scale capable of appropriately securing the response speed and the weighing accuracy regardless of the unit weight of an article to be weighed. And

[0012]

In order to solve the above-mentioned problems, the invention of claim 1 weighs a set of articles,
A counting scale for counting the number of the articles included in the set, a weighing signal that detects the weight is input, and stability determining means for determining whether the weighing signal is temporally stable; and A determination condition changing unit that changes a determination condition in the stability determination unit according to the unit weight of the article, wherein the determination condition changing unit widens the determination condition when the unit weight is relatively large, When the unit weight is relatively small, the determination condition is narrowed.

According to a second aspect of the present invention, in the counting scale according to the first aspect of the present invention, the stability determining means determines that the temporal fluctuation width of the weighing signal is smaller than a predetermined stabilization width. The weighing signal is determined to be stable, and the determination condition changing means sets the stabilization width to be large when the unit weight is relatively large, and to set the stabilization width when the unit weight is relatively small. Stabilizing width changing means for setting the width to be small.

According to a third aspect of the present invention, in the counting scale according to the first or second aspect, the stabilizing width changing means changes the stabilizing width in proportion to the unit weight of the article. .

According to a fourth aspect of the present invention, in the counting scale according to any one of the first to third aspects, a change in the weighing signal is reflected on an input of the stability determining means in accordance with the unit weight of the article. Speed changing means for changing a temporal reflection speed in causing the speed to be changed, wherein the speed changing means increases the temporal reflection speed when the unit weight is relatively large, and when the unit weight is relatively small. The time reflection speed is reduced.

According to a fifth aspect of the present invention, there is provided a counting scale for weighing a set of articles and counting the number of the articles included in the set, wherein a weighing signal for detecting the weight is inputted. A stability determining unit that determines whether the weighing signal is temporally stable, and a temporal reflection when reflecting a change in the weighing signal to an input of the stability determining unit according to the unit weight of the article. Speed changing means for changing the speed, wherein the speed changing means increases the temporal reflection speed when the unit weight is relatively large, and increases the temporal reflection speed when the unit weight is relatively small. I'm lowering it.

[0017]

Before describing the specific configuration and operation of the embodiment of the present invention, the principle of the present invention will be described with reference to a specific example.

FIG. 1 is a diagram showing a configuration of a signal processing section of a general counting scale, and shows a basic portion to be controlled in a configuration (FIG. 7 described later) of the embodiment of the present invention.

The signal processing section 20 includes an amplifier 21, an A / D converter 22, a low-pass filter 23, and a stability determination section 24. The article weighing signal detected by the weight detector 10 is amplified by the amplifier 21, converted into a digital signal by the A / D converter 22, and the high-frequency component is removed by the low-pass filter 23. This low-pass filter 2
The weighing signal processed by 3 is input to the stability determination unit 24, and when the fluctuation width within a predetermined time becomes smaller than the predetermined stabilization width, it is determined that the weighing signal has become stable and is output as a weighing value.

FIG. 2 is a diagram in which the weighing signal (hereinafter, referred to as “weighing data”) after being processed by the low-pass filter 23 is plotted. In FIG. 2, a solid line FS1 is an example of a weighing data waveform. FIG. 3 is an enlarged model diagram of a portion (PL2) used for stability determination in the weighing data waveform FS1. In these figures, the horizontal axis represents time, and the vertical axis represents the value (weight) of the weighing data. In FIG. 3, each data is indicated by a white diamond.

The conversion into a digital signal in the A / D converter 22 is performed at a predetermined time interval, and this interval is a sampling pitch. In FIG. 3, the interval of each data in the horizontal axis direction is the sampling pitch SP. Also, A
In the / D converter 22, quantization for applying the amplitude of the analog input signal to the digital level is performed, and the unit width of the digital level is the quantization width. In FIG. 3, the minimum interval between the data in the vertical axis direction is the quantization width W2.

As described above, the stability determination unit 24 determines that the stability has been achieved when the fluctuation width of the predetermined determination time WT of the input weighing data is smaller than the predetermined stabilization width W1, and determines that the weighing data has been stabilized. Is output as This determination time WT
Means that a predetermined number of determinations N (N ≧
2) is given. Specifically, from the point of time of certain data (P1 in the example of FIG. 3), the number of determinations N (FIG.
If the variation width is smaller than the stabilization width W1, the stability determination unit 24 determines that the weighing data is stable. That is, it is determined that the data is stable at the time point of the data after the number of determinations N (P2 in the example of FIG. 3). The stability determination section 24 takes the value of the center of the stabilization width W1 and outputs it as final measurement data.

In the processing of the stability determination section 24, the stability determination conditions used to determine that the stability has been established include a "stabilization width" W1, a "quantization width" W2, and a "number of determinations" N. Hereinafter, each setting will be described.

The stabilization width W1 defines whether the allowable fluctuation width at the time of stability determination is increased or decreased. That is, increasing the stabilization width W1 means that the variation width allowed for the determination is increased, and is equivalent to ignoring small variations in the weighing data. As a result, the response speed is determined to be faster and more stable, and the response speed is improved. However, if the stabilization width W1 is wide, there is a possibility that it may be determined that the measurement value is stable at a value other than the original measurement value, so that the measurement accuracy is reduced. Conversely, if the stabilization width W1 is reduced, the response speed is reduced, but the weighing accuracy is improved.

The quantization width W2 defines how much a minute change in the amplitude of the analog weighing signal is reflected during A / D conversion. That is, increasing the quantization width W2 corresponds to being converted into the same quantization level by being absorbed by the quantization width W2. As a result, it is determined to be faster and more stable, and the response speed is improved. However, a wide quantization width W2 cannot reflect a slight change in the weighing signal indicating the original weight of the weighing object, so that the weighing accuracy is reduced. Conversely, if the quantization width W2 is reduced, the response speed is reduced, but the measurement accuracy is improved.

The number of determinations N specifies whether to shorten or lengthen the determination time WT obtained by multiplying the sampling pitch SP in the stability determination by the number of determinations N. That is, reducing the number of determinations N shortens the determination time WT of the stability determination. As a result, it is determined to be faster and more stable, and the response speed is improved. However, reducing the number of determinations N may result in the possibility of being determined to be stable at a time when the measurement is not actually stable, and the weighing accuracy is reduced. Conversely, if the number of determinations N is increased, the response speed is reduced, but the weighing accuracy is improved.

As described above, each of the above-mentioned discrimination parameters defines the “width” of the stabilization condition. In this specification,
(1) In general, a setting that relatively widens the range of the state satisfying the stabilization condition, such as increasing the stabilization width W1, increasing the quantization width W2, and reducing the number of determinations N, is set to be stable. (2)
In general, a setting that narrows the range of the state satisfying the stabilization condition, such as narrowing the stabilization width W1, narrowing the quantization width W2, and increasing the number of determinations N, is described below. Called "narrow."

Also, the stability determination condition can be expressed by different terms, such as "wider" and "relaxed" and the stability determination condition of "narrower" as "stricter".

To summarize the above description, when the stability determination condition is set to "wide", the response speed is improved and the weighing accuracy is reduced. Conversely, when the stability determination condition is "narrow", the response speed is reduced and the weighing accuracy is improved.

The condition for changing the time reflection speed for reflecting the change of the weighing signal input to the stability determination unit 24 to the weighing data includes “sampling pitch”.
SP, "cutoff frequency" CF. Hereinafter, the change of each setting will be described.

The sampling pitch SP defines whether to shorten or lengthen the timing at which the time variation is periodically reflected. That is, when the sampling pitch SP is shortened, a change in the weighing signal is reflected in the weighing data at an early stage, so that the temporal reflection speed on the weighing data is increased, and the determination time WT of the stability determination is shortened. It will be. As a result, it is determined to be faster and more stable, and the response speed is improved. However, shortening the sampling pitch SP may be determined to be stable at a time when it is not actually stable, and the weighing accuracy is reduced. Conversely, if the sampling pitch SP is made longer, the time reflection speed is reduced and the response speed is reduced, but the weighing accuracy is improved.

The low-pass filter 23 removes vibration noise having a frequency higher than the frequency set as the cutoff frequency CF. When the cutoff frequency CF is increased, the vibration noise that can be removed is limited to frequencies higher than the cutoff frequency CF, so that the accuracy of the weighing signal decreases. When the cutoff frequency CF is reduced, the accuracy of the weighing signal improves. In FIG. 2, a dashed-dotted line FS2 shows a weighing data waveform obtained by increasing the cutoff frequency CF with respect to the weighing data waveform FS1.
If the cutoff frequency CF is increased as shown in FIG. 2, a sharp change in the weighing signal is also reflected in the weighing data.
This will increase the speed of temporal reflection on weighing data. That is, the cutoff frequency CF of the low-pass filter 23
Increasing the response speed increases the temporal reflection speed and improves the response speed, but decreases the weighing accuracy.
Conversely, when the cutoff frequency CF of the low-pass filter 23 is reduced, the time reflection speed is reduced and the response speed is reduced, but the weighing accuracy is improved.

To summarize the above description, when the time reflection speed is increased, the response speed is improved and the measurement accuracy is reduced. Conversely, when the time reflection speed is "decreased", the response speed is reduced and the weighing accuracy is improved.

Conventionally, on a counting scale,
These stability determination conditions and temporal reflection speeds could not be changed once they were set. That is, in the same stability determination condition and setting of the temporal reflection speed,
Both relatively heavy and relatively light weight articles had to be weighed.

Therefore, when weighing an article having a relatively large unit weight, even if the amplitude of the vibration contained in the weighing signal is large as shown by the waveform FSH in FIG. Response speed was poor due to instability. On a counting scale, the net result may be that the number of articles to be weighed is exactly known, and for relatively large articles of a single weight, the weighing accuracy for the total weight may be relatively low. Therefore, the response speed can be improved by lowering the measurement accuracy. That is, for articles having a relatively large unit weight, the stability determination condition is set to “wide”,
What is necessary is to "increase" the time reflection speed.

Conversely, when weighing an article having a relatively small unit weight, the amplitude of the vibration contained in the weighing signal is small as shown by the waveform FSL in FIG. In some cases, it was not possible to obtain an accurate weighing value. For this reason, if the response speed is reduced so that it is not immediately determined to be stable, the weighing accuracy will be improved. That is, for an article having a relatively small unit weight, the stability determination condition may be "narrowed" and the temporal reflection speed may be "lowered".

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <1. First Embodiment> FIG.
FIG. 1 is a perspective view of a counting scale according to a first embodiment of the present invention. This counting scale 1 has a function of counting the number of articles by measuring the set of articles after setting the unit weight of the articles.

The counting scale 1 shown in FIG. 6 includes a weight detector 10 and an operation panel 50. The weight detector 10 detects the weight of an article placed on its upper surface by using a load cell (not shown) and outputs an analog weighing signal.

The operation panel 50 includes an input key 51 and a liquid crystal display screen 52 having a function as a touch panel. The operator can input necessary data and commands to the counting scale 1 via the input keys 51 and the display screen 52 as a touch panel while confirming the contents displayed on the display screen 52.

The counting scale 1 is a CP
A microcomputer (not shown) including a U, a ROM, a RAM, a non-volatile memory, and the like is provided, and is capable of controlling operation of an operation panel and the like and control of various signal processing.

FIG. 7 is a block diagram showing a functional configuration relating to the processing of the weighing signal of the counting scale 1. The counting scale 1 has a weight detecting unit 10 therein.
Signal processing unit 2 that processes the weighing signal detected in
0, a number counting unit 30 that counts the number based on the weighing data processed by the signal processing unit 20, and a signal processing unit 20
And a determination control unit 40 for controlling the various conditions.

The signal processing section 20 includes an amplifier 21 for amplifying the analog weighing signal SA detected by the weight detecting section 10.
And an A / D converter 22 for converting the amplified analog weighing signal into a digital weighing signal, a low-pass filter 2 for removing high-frequency components of the digital weighing signal to obtain weighing data SD.
3, and a stability determination unit 24 for inputting the weighing data SD and determining whether or not the measurement is stable.

The number counting section 30 receives the weighing value SV processed by the signal processing section 20 and divides the weighing value SV by a predetermined unit weight of the article to count the number of articles. Is output to the display screen 52 as the final counting result.

The determination control unit 40 is realized by the microcomputer described above, and is capable of setting various conditions in the process of processing the weighing signal by the signal processing unit 20, that is, parameters for the stability determination condition and the time reflection speed. . Specifically, the A / D converter 22 has parameters of “sampling pitch” and “quantization width”, the low-pass filter 23 has a parameter of “cutoff frequency”, and the stability determination section 24 has “stabilization”. The parameters of "width" and "number of determinations" can be set variably.

Default values are set for these determination parameters. The default value is an average value of the maximum weighable unit weight and the minimum weighable unit weight that can be measured on the counting scale 1, and the most appropriate value for weighing a unit weight object is experimentally determined in advance. Is set.

Next, the processing contents of the counting scale 1 will be described. The counting scale 1 sets the unit weight of the article to be weighed, sets each discrimination parameter according to the set unit weight, and then measures the set of articles to count the number. ing.

FIG. 8 is a diagram showing a process of setting the unit weight of the article to be weighed and a process of setting each discrimination parameter of the counting scale 1. First, a command button as to whether or not to set the unit weight M is displayed on the display screen 52, and an inquiry is made to the operator (step S1). The operator can make a selection by touching a command button displayed on the display screen 52 as a touch panel. Here, when it is selected not to set the unit weight M, only the weighing process without counting the articles is performed. In this case, each determination parameter is not changed, and the default value is maintained (step S2).

When it is selected to set the unit weight M, a setting process of the unit weight M is performed (step S3). FIG. 9 is a diagram showing the flow of the unit weight M setting process. First, the operator is inquired about the setting method of the unit weight M via the display screen 52.
The operator can select from key input, table designation, and actual measurement.

The key input is to directly input the value of the unit weight of the article to be weighed by the input key 51. When the operator knows the standard of the unit weight of the articles to be weighed, the unit weight M is set by performing this operation (steps S38 and S39).

The table designation is to call the article table from the non-volatile memory of the counting scale 1 and set the unit weight M. This article table is stored in advance in the nonvolatile memory in association with the names of articles frequently weighed in the counting scale 1 and their unit weights. When this table designation is selected, the counting scale 1 calls the article table,
A list is displayed on the display screen 52 (step S36). The operator selects and selects an item from the displayed list, thereby setting and selecting the unit weight M (step S36, step S39).

In the actual measurement, the weight of the article to be counted is calculated by
The actual weight M is set on the counting scale 1 to set the unit weight M. When this measurement is selected, the operator places a predetermined number of articles, for example, 10 articles, on the counting scale 1 (step S31), and displays the display screen 52.
The number of the article is input as 10 (step S3).
2).

After inputting the number, the counting scale 1 weighs the article, and divides the weighing result by the number of the article to calculate a provisional unit weight. In this weighing operation, each determination parameter is set to a default value. Then, the provisional unit weight is displayed on the display screen 52 and stored in the RAM (step S33). at this point,
The operator can select whether to end the actual measurement work (step S34). In order to calculate an accurate unit weight, it is preferable to repeat the actual measurement work several times. If the measurement is not completed, the process returns to step S31 and the actual measurement is performed again.

This actual measurement operation is repeated several times, and when the end is selected in step S34, the counting scale 1 reads out all the temporary unit weights stored in the RAM and calculates the average value (step S34). S35), the calculated average value is set as the unit weight M (step S39).

The unit weight M set in step S3
Is passed to the determination control unit 40. The determination control unit 40 determines in step S5 (S5a, S5b, S5c, S5d, S5
In e), each discrimination parameter is set based on the unit weight M. FIG. 10 is a diagram illustrating a flow of a process in which the determination control unit 40 sets each determination parameter. In the figure, X is a discrimination parameter to be set.

Here, for each discrimination parameter, a threshold value A1 (A1a, A1b, A1) that satisfies "maximum weighable unit weight>A1> average value of weighable unit weight>A2> minimum weighable unit weight"
c, A1d, A1e) and the threshold value A2 (A2a, A2
b, A2c, A2d, A2e) are set in advance.

Further, parameter values B0 (B0a, B0b, B0c, B0d, B0e) for each discrimination parameter,
B1 (B1a, B1b, B1c, B1d, B1e) and B2 (B2a, B2b, B2c, B2d, B2e)
Is set. The parameter value B0 is a default value of the X parameter. The parameter value B1 is a value that “widens” the X parameter compared to the default value B0 if the X parameter is a stability determination condition, and is X compared to the default value B0 if the X parameter is a temporal reflection speed. Value to "increase" the parameter. Further, the parameter value B2 is a value for "narrowing" the X parameter as compared with the default value B0 when the X parameter is a stability determination condition, and is compared with the default value B0 when the X parameter is a temporal reflection speed. Is the value by which the X parameter is "decreased".

First, the determination control section 40 performs a setting process of a stabilization width parameter in step S5a. Step S5
At the time of 0, the stabilization width parameter is a default value B0a. In step S50, the unit weight M and the threshold A
1a and A2a are compared. Here, if the unit weight M is larger than A1a, it is determined that the unit weight is relatively large, and the stabilization width parameter is set to a parameter value B1a that makes the stabilization width “wider” than the default value B0a (step S1). S51). In step S50, the unit weight M is A2.
If it is smaller than a, the unit weight is determined to be relatively small, and the stabilization width parameter is set to a parameter value B2a that makes the stabilization width “narrower” than the default value B0a (step S53). When the unit weight M is smaller than A1a and the unit weight M is larger than A2a in step S50, the stabilization width parameter is not changed from the default value B0a (step S52). By the processing of the determination control unit 40, the stabilization width parameter of the stability determination unit 24 is set to a parameter value corresponding to the unit weight M.

Further, the determination control section 40 sets the quantization width parameter of the A / D converter 22 according to the unit weight M by the same processing (see FIG. 10) (step S5b).
The determination number parameter of the stability determination unit 24 is set (step S5c), the sampling pitch parameter of the A / D converter 22 is set (step S5d), and the cutoff frequency parameter of the low-pass filter 23 is set (step S5d). S5e).

As described above, when the unit weight is relatively large, the response speed is improved by widening the stability determination condition and increasing the time reflection speed, and the unit weight is relatively small. In some cases, the weighing accuracy is improved by narrowing the stability determination condition and increasing the temporal reflection speed. As a result, the response speed and the measurement accuracy can be appropriately secured in one counting scale.

<2. Second Embodiment> Next, a second embodiment of the present invention will be described. In the first embodiment, the stabilization width parameter is determined by setting the unit weight M to the threshold A1.
Although the parameter values B0a, B1a, and B2a are set in advance in comparison with the parameter values a and A2a, in the second embodiment, the value of the stabilization width is proportional to the unit weight M,
For example, it is different in that it is に す る of the unit weight M. The configuration of the counting scale 1 in the present embodiment is the same as that shown in FIGS.

Here, the setting of the stabilization width to の of the unit weight M will be described. Consider a case where 100 articles having a single unit weight m are weighed by the counting scale 1. The weighing data SD input to the stability determination unit 24
Is counted as it is without determining that it is stable.
Is divided by the unit weight m. If the result of the division has a fluctuation range of, for example, 95.0 to 105.0, the number cannot be specified. However, if the variation width is, for example, from 99.5 to 100.4, it can be specified as 100. In other words, if the stabilization width fluctuates within a range of 100 to 1/2, then 10
That is, it can be specified as zero. Here, since the width of 1/2 is 1/2 of the unit weight m, the stabilization width is 1/1 of the unit weight m.
It can be said that the number can be specified by 2.

FIG. 11 is a diagram showing a process of setting the unit weight of an article to be weighed and a process of setting a stabilization width and other various parameters of the counting scale 1 in the present embodiment. The flow of processing in steps S1, S2 and S3 is the same as in the first embodiment.

The unit weight M set in step S3
Is passed to the determination control unit 40. The determination control unit 40 sets the value of the stabilization width of the stability determination unit 24 to の of the unit weight M (step S4). Here, the stabilization width is set to 1/2 of the unit weight M, but it is needless to say that the unit weight M may be multiplied by a numerical value of 1/2 or less.

Further, the judgment control unit 40 performs the same processing (see FIG. 10) as in the first embodiment,
The quantization width parameter of the A / D converter 22 is set (step S5b), and the number of determinations parameter of the stability determination unit 24 is set (step S5c).
The sampling pitch parameter 2 is set (step S5d), and the cutoff frequency parameter of the low-pass filter 23 is set (step S5e).

As described above, the response speed is improved when the unit weight is relatively large, the weighing accuracy is improved when the unit weight is relatively small, and the stabilization width is changed in proportion to the unit weight. This makes it possible to finely determine the stabilization conditions.

<3. Modifications> The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above embodiment, all of the stability determination condition and the temporal reflection speed
However, only an arbitrary one of them may be set according to the unit weight M.

In the above embodiment, the number of thresholds is two, but any number may be used. For example, if the number of thresholds is three or more, finer settings can be made more gradually. If the number of thresholds is one, the present invention can be applied with a simpler configuration.

In the above embodiment, the default value is set based on the average value of the maximum weighable unit weight and the minimum weighable unit weight. However, the default value is set to the minimum weighable unit weight. Is also good. In other words, the default value is set to the setting with the highest weighing accuracy, the unit weight M is compared with a plurality of thresholds, the stability determination condition is gradually increased, and the time reflection speed is increased. Is also good. Conversely, the default value is set to the best response speed, the unit weight M is compared with a plurality of thresholds, the stability determination condition is gradually narrowed, and the temporal reflection speed is gradually lowered. You may do so.

[0069]

As described above, according to the first aspect of the invention, by changing the discriminating condition in accordance with the size of the unit weight of an article, a unit having a relatively large unit weight is substantially changed. The response speed can be improved without sacrificing the accuracy of the result of counting the articles, and the measurement speed can be improved by lowering the response speed if the unit weight is relatively small.

Therefore, it is possible to provide a counting scale capable of appropriately securing the response speed and the weighing accuracy irrespective of the unit weight of the articles to be weighed.

According to the second aspect of the present invention, by changing the stabilization width according to the unit weight of the article, the response speed is improved when the unit weight is relatively large, and the weighing is performed when the unit weight is relatively small. The accuracy is improved.

According to the third aspect of the present invention, the stabilization condition can be finely determined by changing the stabilization width in proportion to the unit weight of the article.

According to the invention of claim 4, in order to change the temporal reflection speed according to the unit weight of the article,
The response speed and weighing accuracy can be changed according to the unit weight.

According to the fifth aspect of the present invention, the response speed and the weighing accuracy can be changed according to the unit weight in order to change the time reflection speed according to the unit weight of the article.

Therefore, it is possible to provide a counting scale capable of appropriately securing the response speed and the weighing accuracy regardless of the unit weight of the article to be weighed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a signal processing unit of a counting scale.

FIG. 2 is a diagram in which a weighing signal processed by a low-pass filter is plotted.

FIG. 3 is an enlarged model diagram showing a plot of a filtered signal.

FIG. 4 is a diagram plotting a filtered signal when the unit weight is relatively large.

FIG. 5 is a diagram plotting a filtered signal when the unit weight is relatively small.

FIG. 6 is a perspective view of a counting scale according to the present invention.

FIG. 7 is a block diagram showing a functional configuration relating to processing of a weighing signal of the counting scale of FIG. 6;

FIG. 8 is a diagram illustrating a setting process of various parameters according to the first embodiment.

FIG. 9 is a diagram showing a flow of a unit weight setting process.

FIG. 10 is a diagram showing a flow of processing for setting each parameter.

FIG. 11 is a diagram illustrating a setting process of various parameters according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Counting scale 10 Weight detection part 20 Signal processing part 21 Amplifier 22 A / D converter 23 Low-pass filter 24 Stability judgment part 30 Number counting part 40 Judgment control part 50 Operation panel A1, A2 Threshold value B0 Default value B1, B2 Parameter value M Unit weight W1 Stabilization width W2 Quantization width N Number of judgments SP Sampling pitch CF Cutoff frequency

Claims (5)

[Claims] 1. A counting scale for measuring the weight of a set of articles and counting the number of the articles included in the set, wherein a weighing signal for detecting the weight is input, and the weighing signal is time-dependent. Stability determination means for determining whether or not the stability has been established; and determination condition changing means for changing a determination condition in the stability determination means according to the unit weight of the article. A counting scale, wherein when the weight is relatively large, the determination condition is widened, and when the single weight is relatively small, the determination condition is narrowed. 2. The counting scale according to claim 1, wherein the stability determination unit determines that the weighing signal is stabilized when a temporal fluctuation width of the weighing signal becomes smaller than a predetermined stabilization width. The determination condition changing means sets the stabilization width to be large when the unit weight is relatively large, and sets the stabilization range to be small when the unit weight is relatively small. A counting scale, comprising: changing means. 3. The counting scale according to claim 1, wherein the stabilizing width changing unit changes the stabilizing width in proportion to the unit weight of the article. 4. The counting scale according to claim 1, wherein a change in the weighing signal is reflected on an input of the stability determination means in accordance with a unit weight of the article. A speed changing unit for changing the time reflecting speed when the unit weight is relatively large, and decreasing the time reflecting speed when the unit weight is relatively small. A counting scale characterized by: 5. A counting scale for measuring the weight of a set of articles and counting the number of the articles included in the set, wherein a weighing signal for detecting the weight is input, and the weighing signal is time-dependent. Stability determining means for determining whether or not the stability has been established; and speed changing means for changing a temporal reflection speed in reflecting a change in the weighing signal to an input of the stability determining means in accordance with the unit weight of the article. Counting, wherein the speed changing means increases the temporal reflection speed when the unit weight is relatively large, and decreases the temporal reflection speed when the unit weight is relatively small. scale.