JP2810509B2 - Electronic weighing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic weighing device for weighing goods, and more particularly to an electronic weighing device for weighing goods being transported by a weighing conveyor.

[Prior art] Conventional electronic weighing equipment not only weighs products, but also calculates the price from the weight value and unit price of the product, and puts the calculated price on the label along with the product name and weight value of the product. There is a weighing device for printing.

Recently, a full-auto type automatic weighing and weighing apparatus has been developed in order to process the above weighing and weighing work at high speed and in large quantities.

In this apparatus, a weighing conveyor is arranged on the upstream side of a product transport line, and a label printing / sticking unit is arranged on an upper portion of the downstream side. Then, this device weighs the goods during the transfer by the weighing conveyor, calculates the price of the goods based on the weighed value, prints the calculated price, the product name, the weight value, etc. on a label. The printed label is automatically attached to the goods being transported by blowing with air. In addition, this device has a maximum of 80
The goods in the pack can be weighed and priced.

"Problems to be Solved by the Invention" By the way, in the above-mentioned conventional electronic weighing device, particularly, in a high-speed type automatic weighing and weighing device, one of the technical problems to be solved is to perform accurate weighing. .

That is, since the goods are weighed during the transfer in order to increase the processing speed, the weighed value fluctuates and becomes unstable. Therefore, in this type of apparatus, the weighing value of the product is sampled and stored a plurality of times, and the plurality of weighing values immediately before the product is unloaded from the weighing conveyor (the vibration is most stable) are averaged. The weight of the product (see Japanese Patent Application Laid-Open No. 60-213318).

In this type of apparatus, since the average value of the weighing values is obtained and used as the weight value of the product, an accurate weighing value can be obtained when the vibration of the weighing value is stable.

However, recently, in order to perform higher-speed processing, the transportation speed of the product has been further increased, and it is difficult to stabilize the vibration.

Further, in order to reduce the size of the apparatus, the length of the weighing conveyor tends to be shortened, and in this case, the vibration is hardly stabilized. In particular, when the product moves or tilts in the tray during weighing, stable vibration is not obtained, and an accurate weighing value cannot be obtained.

Further, even when the weighing conveyor itself violates due to an earthquake or a person hitting the apparatus, an accurate weighing value cannot be obtained.

If a measurement error occurs due to the various causes described above, the content of the product may be displayed in a larger amount than the actual one, and a serious problem such as incorrect display may occur.

The present invention has been made in view of the above circumstances, and has as its object to provide an electronic weighing device that can obtain an accurate weighing value even when a product shakes on a weighing conveyor or when the weighing conveyor itself vibrates. And

[Means for Solving the Problems] The invention according to claim 1, wherein the carry-in conveyor, the weighing conveyor, and the carry-out conveyor are arranged in order, and the carry-in conveyor is an electronic weighing device that weighs goods being transferred by the weighing conveyor. Storage means for sampling the weighing data until the goods conveyed one by one to the weighing conveyor until the goods are transferred to the unloading conveyor, and storing a plurality of sampled latest weighing data;
Detecting means for detecting the start of unloading from the weighing conveyor to the unloading conveyor, and average value calculating means for calculating an average by averaging a plurality of weighing data immediately before the detection of the unloading of the product by the detecting means An allowable deviation value determining means for determining an allowable deviation value based on the average value; a determining means for determining whether all of the plurality of weighing data are within the allowable deviation value; and If all the weighing data are within the allowable deviation value, the average value is used as the weighing value, and if there is weighing data that does not fall within the allowable deviation value, the average value is calculated again from the plurality of weighing data excluding the weighing data. And a weighing value determining means for calculating the average value as a weighing value.

According to a second aspect of the present invention, in the first aspect of the present invention, the weighing value determination unit determines that the weighing data is erroneous when the determination unit determines that the weighing data that is not within the allowable deviation value is a predetermined number or more. It is characterized by:

[Operation] According to the first aspect of the present invention, the storage unit stores a plurality of latest sampled weighing data. Further, the detecting means detects the start of unloading of the goods from the weighing conveyor to the unloading conveyor, and the average value calculating means averages a plurality of weighing data immediately before the detection of the unloading of the goods by the detecting means to calculate an average value. Then, the deviation value determining means determines an allowable deviation value based on the average value. Further, the determining means determines whether or not all of the plurality of weighing data are within the allowable deviation value.

Thus, the weighing value determining means sets the average value as a weighing value when all of the plurality of weighing data are within the allowable deviation value, and removes the weighing data when there is weighing data not within the allowable deviation value. An average value is calculated from the plurality of weighing data, and the average value is used as a weighing value.

According to a second aspect of the present invention, in the first aspect of the invention, the weighing value determining unit determines that the weighing data is erroneous when there is a predetermined number or more of the weighing data that is not within the allowable deviation value.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic front view showing an external configuration of a weighing device to which an electronic weighing device according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram showing the electrical configuration.

In these drawings, reference numeral 1 denotes a transfer device, which is a carry-in conveyor 2 for carrying goods in, a goods conveyed by the carry-in conveyor 2, a weighing conveyor 3 for measuring and receiving the goods conveyed by the weighing conveyor 3, The product comprises a labeling conveyor 4 for carrying out labeling work on the product and carrying out the product. The carry-in conveyor 2 is driven by a motor 5, the weighing conveyor 3 is driven by a motor 6, and the sticking conveyor 4 is driven by a motor 7.

Further, a console unit 8 is provided above the weighing conveyor 3 and a weighing unit 9 is provided below the weighing conveyor 3, and the console unit 8 is used for inputting data, displaying the weighing result of the goods by the weighing unit 9, controlling each unit of the apparatus, and the like. I do. Also, the weighing unit 9
Is a load cell 10 that detects the weight of a product and outputs a weight signal and an A / D that converts the weight signal into digital data.
It comprises a converter 11.

Further, a label printing / attaching section 12 including a label printing section 13 and a label applying section 14 is provided above the attaching conveyor 4. The label printing / attaching unit 12 prints out the print data such as the product name and the measurement result transferred from the console unit 8 on the label by the label printing unit 13, and then blows the label downward with compressed air in the label applying unit 14. It is attached to a predetermined position of the product placed on the upper surface of the attaching conveyor 4.

In addition, in the console unit 8 shown in FIG. 2, reference numeral 15 denotes a CPU (central processing unit) which is provided in the console 8 and controls each unit of the apparatus. Reference numeral 16 denotes a ROM, in which a control program used in the CPU 15 is stored. At the same time, the characteristic (described later) of the allowable deviation d with respect to the average weight shown in FIG. 3 is stored in the form of a table or an arithmetic expression.

Reference numeral 17 denotes a RAM, as shown in FIG. 4, a flag / register area 18 in which various flags and registers are secured,
A preset data area (product file) 19 in which data such as a product name and a unit price according to the product code is stored, and a total data area (to store total data of sales quantity, sales weight, and sales amount) according to the product code ( Achievement file) 20.

Further, the flag register area 18, the weight register 18a latest 50 weight data w ₁ to w _50, which is sampled at a predetermined time is stored, the average weight of the weight data w ₁ to w ₅₀ is stored average The weight register 18b has a characteristic (third characteristic) of the allowable deviation d stored in the ROM 16 with respect to the average weight.
Tolerance d obtained from the average weight based on figure)
Is stored in an allowable deviation register 18c and the like.

Of these, the weight register 18a is, as shown in FIG.
It is configured to store ₅₀ latest weight data (w _{1 to} w ₅₀ ). That is, now, new when the latest data is stored in the area 18a _n as a weight data w _n is sampled, the weight data w _n the previously sampled
Is stored in the area 18a _(n-1) , and the weight data w _n-1 is stored in the area
18a _(n-2) , etc.
Weight data w ₁ which has been stored in the area 18a ₁ is discarded.

In the console unit 8 shown in FIG. 2, reference numeral 21 denotes an operation unit disposed on the front of the console unit 8, and a unit price, a product name, a commercial message, and the like can be input by an operator's operation. Reference numeral 22 denotes a display unit on which a product name, a unit price, and the like are displayed, and reference numeral 23 denotes a weighing unit interface through which the CPU 15 exchanges data with the weighing unit 9.

Reference numeral 24 denotes a motor control interface. When the CPU 15 controls the motor control circuit 25 via the motor control interface 24, the motors 5 to 7 for driving the carry-in conveyor 2, the weighing conveyor 3, and the sticking conveyor 4, respectively, are rotationally driven. Is done.

Reference numeral 26 denotes a sensor interface, and the CPU 15 controls the sensors 27 to 30 to be described later through the sensor interface 26.
Input signal.

1 and 2, a sensor 27 detects that the commodity has reached the end of the carry-in conveyor 2 on the side of the weighing conveyor 3, and a sensor (detection means) 28
It is detected that the carry-out of the goods is started from. And
These sensors 27 and 28 are provided to control the conveyance of the goods so that two or more goods are not carried into the weighing conveyor 3 during the measurement of the goods. That is, when the start of unloading of the product from the weighing conveyor 3 is detected by the sensor 28, the carry-in conveyor 2 is driven to load one product into the weighing conveyor 3. Also, the weighing conveyor 3 is detected by the sensor 28.
If the product is detected by the sensor 27 before the start of carrying out of the product from is detected, the carry-in conveyor 2 is stopped.

The sensor 29 is a sensor that detects immediately before a product is carried out from the weighing conveyor 3 to the attaching conveyor 4. This sensor
When a product is detected by 29, a process of determining a weight value to be printed on a label, which will be described later, is started. This is because the vibration of the weighing value is most attenuated immediately before the product is carried out of the weighing conveyor 3 and is stable.

The sensor 30 is a sensor that detects a product in order to attach a label to the product. As shown in FIG. 6, after the product 31 is detected by the sensor 30, the label printing / attaching section 12 blows air toward the product 31 and affixes the label 32 after a certain period of time, whereby the product 31 is always detected. A label 32 is attached to a position determined from the end of 31.

In such a configuration, in order to attach a label corresponding to a product to a product, the operator first inputs the product number (product number) of the product from the operation unit 21 of the console unit 8 and Set data such as unit price and product name. Then, when the worker places the product on the carry-in conveyor 2, the product is transported by the carry-in conveyor 2 and delivered to the weighing conveyor 3. The weighing conveyor 3 receives the goods,
The weighing unit 9 provided at the lower part of the weighing conveyor 3 measures the weight and transfers the weight data to the CPU 15. Specifically, the CPU 15 constantly samples the weight data transferred from the weighing unit 9 at predetermined time intervals (for example, about once every 10 msec), and constantly samples the latest 50 weight data (w ₁ to w ₁ ).
w ₅₀ ) is stored in the weight register 18 a of the flag register area 18 of the RAM 17.

It will now be described with reference to the flowchart of FIG. 7 for CPU15 of operation of determining the weight value to be printed on a label on the basis of the weight data w ₁ to w _50. When the sensor 29 detects a product, that is, when the product on the weighing conveyor 3 is transported until just before unloading is detected, CPU 15 proceeds to step S1, the additive of the weight data w ₁ to w ₅₀ After calculating the average based on the following equation and storing it in the average weight register 18b of the flag register area 18 of the RAM 17, the process proceeds to step S2.

In step S2, the allowable deviation d is determined from the average weight based on the characteristic of the allowable deviation d with respect to the average weight (see FIG. 3) stored in the ROM 16, and the allowable deviation register 18c of the flag register area 18 of the RAM 17 is determined. After that, the process proceeds to step S3.

In step S3, after calculating the absolute value d ₁ of the difference between the average weight and the weight data w _{i (i} = 1~50) based on the following equation, the process proceeds to step S4.

d _i = | −w _i | In step S4, it is determined whether or not any of the absolute values d _i (i = 1 to 50) is larger than the allowable deviation d. If the result of this determination is “NO”, that is, w _{1 to} w ₅₀ are all the eighth
As shown in the figure, if the value is within the allowable range between the value (−d) and the value (+ d), the process proceeds to step S5. The eighth
In the figure, the time t ₁ indicates the time the product is detected by the sensor 29.

In step S5, it is determined that an accurate weighing value has been obtained, and the average weight is determined as the weight value of the product. Then, the process returns to the main routine.

On the other hand, when the result of determination in step S4 is "YES", i.e., if is outside the allowable range described above even one of the weight data w _i, the process proceeds to step S6.

In step S6, the weight data w _i that is outside the allowable range is a predetermined number, for example, it determines whether there is more than 10. If the result of this determination is “YES”, the flow proceeds to step S7.

In step S7, it is determined that an accurate weighing value has not been obtained, a flag indicating that the weighing has failed (provided in the flag register area 18 of the RAM 17 described above) is set, and then the process returns to the main routine.

On the other hand, if the result of the determination in step S6 is "NO",
If the weight data w _i that is outside the allowable range is less than 10 (e.g., as shown in FIG. 9, when only the weight data w ₂ is out of the allowable range), the process proceeds to step S8. In FIG. 9, time t ₁ indicates the time at which a product is detected by the sensor 29, as in FIG.

In step S8, first, calculating a new average weight 'except (weight data w ₂ in the case of FIG. 9) weight data w _i that is outside the allowable range from the weight data w ₁ to w _50. Then, after determining the obtained average weight ′ as the weight value of the product, the process returns to the main routine.

Next, the CPU 15 calculates the price of the product based on the weight value and the unit price of the product obtained by the above-described processing. Then, the CPU 15 displays the weight value on the display unit 22 and transfers the print command and the print data including the weight value to the label print sticking unit 12.

Next, the commodity 31 is transferred from the weighing conveyor 3 to the attaching conveyor 4 and is conveyed by the attaching conveyor 4. And
After a lapse of a predetermined time from the detection by the sensor 30, the light reaches the position immediately below the label printing / sticking unit 12.

On the other hand, the label print attaching section 12 receives the print command and print data transferred from the CPU 15 and
Is performed on the label 32 based on the print data transferred from the CPU 15.

Then, the label attaching section 14 detects the product 31 by the sensor 30.
When a predetermined period of time has elapsed after the detection of is performed, air is blown toward the product 31 to attach the label 32.

On the other hand, if the weighing failure flag is set in the process of step S8 described above, the label printing / sticking process is not performed.

For this reason, the operator can determine that the weighing has failed if any of the products has no label attached after the label printing / attaching process is completed for all the products. When the weighing failure flag is set in the processing of step S8 described above, the operation of the apparatus may be stopped and an alarm to that effect may be issued.

As described above, the present invention causes a measurement error,
That is, the correct weight value causes no (true value) is obtained is because seeking average weight, including the weight data w _i which deviates greatly from the true value, the weight data largely deviates from the true value Calculating the average weight, excluding w _i , is based on a theoretical guess that a more accurate, ie, closer to true, metric value should be obtained.

Then, in one embodiment described above, in order to find the weight data w _i which deviates greatly from the true value, is used tolerance d determined from the average weight. However, if there is weight data deviates extremely from the true value is accurate weight values are expected may not be obtained, the weight data w _i is not within the allowable deviation in this case there are many it means that, when there is no weight data w _i in the tolerance is equal to or greater than a predetermined number are to be treated as erroneous metering.

In the above-described embodiment, it has been confirmed by experiments that more accurate measurement values can be obtained as compared with the related art.

In the above-described embodiment, the weighing device is described, but the present invention is not limited to this. In short, the present invention is applicable to any electronic weighing device that averages the sampled weighing values to obtain the final weight value.

Further, in the above-described embodiment, an example in which the sampling interval of the weighing value is a fixed time is shown, but as described in Japanese Patent Application Laid-Open No. You may make it do.

Further, in the above-described embodiment, the characteristic diagram with respect to the average weight of the permissible deviation d is obtained by the experiment shown in FIG. 3, but is not limited thereto. It is also conceivable to calculate a permissible deviation d by obtaining a second-order or higher polynomial.

In addition, in the above-described embodiment, the characteristic of the allowable error d with respect to the average weight shown in FIG. 3 is stored in the ROM 16 in the form of a table or an arithmetic expression. You may make it.

[Effects of the Invention] As described above, according to the present invention, even if the goods are shaken on the weighing conveyor or the weighing conveyor vibrates, even if the vibration of the weighing data becomes irregular, the error can be reduced. Since the weighing value is calculated by averaging a plurality of weighing data excluding the weighing data which is likely to cause a cause, more accurate weighing can be performed as compared with the related art.

Further, according to the second aspect of the invention, when the degree of irregularity of the vibration is severe, it is processed as erroneous weighing.

Therefore, the inconvenience such that the content of the product is displayed more than the actual content is solved.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing the external configuration of a weighing device to which an electronic weighing device according to an embodiment of the present invention is applied, FIG. 2 is a block diagram showing the electrical configuration, and FIG. FIG. 4 is a diagram showing an example of a characteristic with respect to the average weight of the RAM1.
7 is a diagram showing an example of the configuration of FIG. 5, FIG. 5 is a diagram showing an example of the configuration of the weight data area 18a of the flag register area 18 of the RAM 17, FIG. 6 is a diagram for explaining the role of the sensor 30, FIG. Figure is a flow chart showing the operation of the CPU15 determining the weight value to be printed on a label on the basis of the weight data w ₁ to w _50,
8 and 9 are diagrams each showing an example of the waveform of the vibration of the sampled weight data. DESCRIPTION OF SYMBOLS 1 ... Conveying device, 2 ... Carry-in conveyor, 3 ... Measuring conveyor, 4 ... Sticking conveyor, 5-7 ... Motor, 8 ...
Console part, 9 ... Measurement part, 10 ... Load cell, 11 ...
… A / D converter, 12… Label printing part, 13… Label printing part, 14… Label pasting part, 15… CPU, 16… ROM,
17 ... RAM, 18 ... Flag register area, 18a ... Weight register, 27-30 ... Sensor.

Claims (2)

(57) [Claims] An electronic weighing apparatus in which a carry-in conveyor, a weighing conveyor, and a carry-out conveyor are arranged in order, and the goods being transported by the weighing conveyor are weighed. Storage means for sampling weighing data before transferring the weighing data to the unloading conveyor, and storing a plurality of sampled latest weighing data, and detecting the start of unloading of the product from the weighing conveyor to the unloading conveyor. Detecting means; average value calculating means for calculating a mean value by averaging a plurality of weighing data immediately before the detection of the product is detected by the detecting means; and determining an allowable deviation value based on the mean value. Allowable deviation value determining means; determining means for determining whether all of the plurality of weighing data are within the allowable deviation value; If all of the several weighing data are within the allowable deviation value, the average value is used as the weighing value.If there is weighing data that is not within the allowable deviation value, the weighing data is excluded from the plurality of weighing data. An electronic weighing device, comprising: a weighing value determining unit that calculates an average value again and uses the average value as a weighing value. 2. The electronic weighing device according to claim 1, wherein the weighing value determining means determines that the weighing data is erroneous when the determining means determines that the weighing data which is not within the allowable deviation value is a predetermined number or more. .