JPH03285121A - Weight sorting apparatus - Google Patents

Abstract

PURPOSE:To improve the measuring accuracy by updating the zero correction based on the average value calculated by an average value calculating means. CONSTITUTION:A timer circuit 15 detects the time without load from when an object is carried out from a transfer conveyor 4 to when a next object is carried onto the conveyor. A subtracter 13 subtracts the zero correction stored in a zero correction memory means 14 from the measuring data of an A/D converter 12. A zero data memory means 16 stores the loadless data output from the A/D converter 12 or subtracter 13. A data number detecting means 17 detects that the sum of a plurality of time without load reaches a predetermined time. A divider 18 and the zero data memory means 16 constituting an average value calculating means calculate the average value of the loadless data stored in the zero data integrating/memory means 16 during the predetermined time when the sum of a plurality of time without load reaches the predetermined time. Then, a zero correction updating means 19 updates the zero correction based on the calculated average value of the average value calculating means.

Description

Detailed Description of the Invention Industrial Field of Application of the Present Invention The present invention measures the weight Φ of the articles carried into the conveyor together with the weight of the conveyor itself using a scale, and uses this weighing signal to calculate the weight of the conveyor. The present invention relates to a weight sorting system 8 that performs sorting judgment on articles based on the weight signal of only articles with a zero correction value corresponding to III subtracted.

<Prior art> On production lines, etc., the weight of products is inspected while they are transported along the line.

A weight sorting device shown in FIG. 4 has conventionally been used for the purpose of weighing articles during transportation.

This weight sorting device 3 receives the articles W from the carry-in conveyor 1 onto the weighing conveyor 4, performs a sorting judgment based on weight while the articles W are conveyed on the weighing conveyor 4, and makes a judgment according to the judgment result. The signal is output to the sorting conveyor 2.

The sorting conveyor 2 sorts and conveys the articles carried out from the weighing conveyor 4 to a conveying route according to the determination result.

Since the weighing device 5 measures the weight of the article as well as the weight of the weighing conveyor 4, in order to perform sorting judgment only on the article If, the total amount of the weighing conveyor 4 itself is subtracted from the weighing signal of the weighing device 5 for correction (zero). correction) is necessary.

For this reason, the zero correction value calculation means 6 calculates the load on which the article is loaded, !, among the weighing signals that vary depending on the shipper of the article, as shown in FIG. [! A predetermined number n of measurement data D] to [)n are taken into the non-load time TO at the opening of the time table W, and the average value DZ is calculated as the zero correction value, and the subtracter 7
to put pressure on.

The signal from the subtracter 7 is input to the determination section 8, which determines the weight of the article at a stable measurement timing of the input signal at the time of the initial product load, and outputs a determination signal.

Note that in many cases, the difference between the articles being carried in and the articles is not constant, and if the non-loading time is short and it is not possible to import the data of r + fIU, n pieces of data are taken again at the next non-loading time. Then, the zero correction value is updated.

Problems to be Solved> However, if the non-load time continues for a long time to be shorter than the time required to update the zero correction value, the zero correction value will not be updated during this period, resulting in a decrease in measurement accuracy.

Particularly in recent years, this type of R-position has been required to have high weighing accuracy and be capable of high-density, high-speed conveyance.
This problem has become serious.

The purpose of this invention is to provide a weight sorting device that solves this problem.

Means to solve problems〉 In order to solve the above problems, the present invention provides a weight sorting device.

an AD converter that converts a weighing signal from a weighing instrument into weighing data; a zero correction value storage means that stores a zero correction value; and after the first item is carried out from the conveyor, carrying in the next article is started. a non-loading time detection means for detecting the non-loading time up to; a subtraction means for subtracting the zero correction value stored in the zero correction value storage means from the measurement data from the AD converter; a non-load data storage means for storing non-load data output from the means; a total i interval determination means for determining that the total of the plurality of non-load times has reached a predetermined time; an average value calculation means for calculating the average value of the non-load data stored in the non-load data storage means during the predetermined time when it is determined that a predetermined time has been reached; and an average value calculated by the average value calculation means. and zero correction value updating means for updating the zero correction value based on the value.

<Operation> Therefore, when the total non-load time reaches a predetermined time, the average value of the non-load data stored during that time is calculated, and the zero correction value is updated based on this average value.

<Example of the present invention> Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the construction of a heavy sorting device 10 according to an embodiment.

In FIG. 1, 11G is a carry-in sensor that detects the start of carrying the first article into the weighing conveyor 4, and detects the carry-in of the article optically using, for example, a light projector/receiver.

12 is an AD converter that converts and outputs the measurement signal from the measuring instrument 5 into P pieces of measurement data per unit FJ#; 13 is an AD converter 12 that converts the zero correction value □z stored in the zero correction value storage means 14; This is a subtracter that subtracts from the metric data value and outputs it.

15 is the time Ta from when a detection signal indicating the start of article loading from the loading sensor 11 is input until the article is completely unloaded, that is, the maximum length of the article W and the conveyance length of the weighing conveyor 4 C. This is a re-trigger type timer circuit for detecting non-loading time that outputs a signal at the "H" level for the time period obtained by dividing the sum of the "H" level by the conveyor speed S.
When , it indicates a state in which there is no article on the weighing conveyor 4, that is, a non-loaded state.

16 is the subtracter 13 while the output of the timer circuit 15 is "H".
The zero data storage means receives unloaded data, that is, zero'''F-Y, output from the zero data storage means, and stores the zero data while sequentially integrating the zero data.

Reference numeral 17 denotes a data number determination means for determining whether the number of zero data accumulated by the zero data accumulation storage means 16 has reached a predetermined value N, and the number of data output P per ψ time of the AD transformer 12 is constant. Therefore, this determination of the number of data indirectly determines the total FfI in the non-load state.

18 is a division that divides the V4 calculation result by a predetermined value N and compares the average value d of the zero data when it is determined that the zero data of Nll has been subjected to M calculation in the zero data 8i calculation storage means 16. It constitutes an average value 2Ij calculation means together with the zero data integration storage means 16.

19 adds this average value d and the zero correction value Qz with the adder 20, uses the added output as a new zero correction value, and performs zero correction via the switch 21 that is turned on when the zero data reaches N@. This is a zero correction value updating means that updates and stores the value in the value storage means 14.

22 determines the entire image of the article based on the data from the subtracter 13 when the article is loaded, that is, the zero-corrected weight f-ta of only the article, and outputs a determination signal according to the determination result to the sorting conveyor 2. This is a means of determining whether

Next, the operation of this medium-sized sorting device 10 will be explained based on the flowchart in FIG. 2 and the signal diagram in FIG. 3.

The weight value of the weighing conveyor 4 is initially set in the zero correction value storage means 14 in advance, and "
It is assumed that 0'' is stored.

First, the output level of the timer circuit 15 is determined, but when the first article is carried in, the output of the carry-in sensor 11 rises to the "H" level at time t1, as shown in FIG. 3(a). As shown in (b) of the same figure, the weight signal from the subtractor 13 increases and changes as the article is carried in, and the output of the timer circuit 15 becomes "off" for a time Ta as shown in (c) of the same figure ( Step 1).

The determination means 22 takes in this weight signal at a timing 7 seconds after a predetermined time from time t1 (timing when the weight signal becomes stable), compares it with a predetermined allowable weight, and generates a determination signal corresponding to the comparison result. (Step 2)
).

During this Ta, the data from the subtracter 13 is not taken into the zero data integration storage means 16 as shown in FIG. 3(d).

If the delivery of the first item of thorns is not started by t2 o'clock when la time yA has passed from 1 o'clock °C, the timer circuit 15 is activated at this t2.
The output rises to "T1".

Therefore, the zero data accumulation storage means 16 stores P-1 until time t3 when the next article is carried in (non-loading time T1).
One piece of zero data is stored and it is determined whether the number of data has reached a predetermined value N (step 3.4).

When the next article starts to be carried in at time t1, the timer circuit 15
The output becomes "Yes" again at time Ta, but if the next article is brought in at time t4 within this time Ta, the timer circuit 15 is retriggered, so the output is "off" again from time t4.
The state is 41I until tS when a time has elapsed! Continue.

During the second non-loading time T2 from time tS to te8i￥ when the next article starts to be carried in, P-12 is used as described above.
The zero data are added to the previous 1a value in the zero data numbing means 16.

Similarly, the third non-load time Ts (from t7 to t9
t8 while zero data integration is being performed
When it is determined that Nil zero data including the number of zero data input during the first and second non-loading times has been input, the average value dSS is obtained, and this average iId is If the value is appropriate (a value between e and f), it is added to the zero correction value stored in the zero correction value storage means 14, and the addition result is updated and stored as a new zero correction value (step 5-7),.

In addition, if the average value d is delayed M times and is transported between e and f, it is assumed that the weighing conveyor 4 is contaminated with scraps or foreign matter, and this final average value is The addition result of d and the zero correction value is updated and stored as a new zero correction value (step 8).

Next, the zero data integration value is reset, and the zero data integration after the reset is performed again (step 9).
).

Note that the third non-loading time is 1.5% due to the influence of the previous stage line, for example. -, and the first further 1frIi(jsIff>
If zero data of NflJ is further input between t5'' and t5'', the second update of the zero correction value is performed continuously.

In addition, in the above explanation, it is assumed that the weight of the weighing conveyor 4 is set in advance as the initial value of the zero correction value, but this zero correction value is set to 07 first, and the average output of the subtraction H13 when no load is applied. The value, that is, the average value of the weighing data from the AD converter 12 (weighing data only from the weighing conveyor 4) may be stored and set in the zero correction value storage means 14 (in this case, the zero correction value storage means 14 may jump from step 5 to step 7). ).

Other Embodiments of the Present Invention In the above embodiments, non-load data (zero data) was taken from the output of the subtracter 13, but the output of the AD converter 12 in the non-load state was taken in as non-load data. The average value may be directly stored in the zero correction value storage means 14 as a new zero correction value.

In addition, in the above embodiment, while importing non-load data, the! f! The brightness value was calculated and stored, but until the total non-load time reaches a predetermined time, only the non-load data is stored, and when the predetermined time is reached, the average value is calculated. You can do it like this.

Further, in the embodiment described above, this predetermined time is determined based on the number of input non-load data, but it is also possible to determine this predetermined time using a clock circuit that uses the output of the timer circuit 15 as a gate pulse. .

Further, if the non-load time is extremely short, the zero data may not be stored in order to prevent the accuracy from decreasing due to the zero data.

Further, the capture resolution of the non-load time may be arbitrarily selected as 1/m (m is an integer).

Effects of the Present Invention> As explained above, the weight sorting device of the present invention continuously captures non-load data until the total non-load time reaches a predetermined time. Even if the non-load time of .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing the processing procedure of the embodiment, and FIG.
The figure is a signal diagram for explaining the operation of the embodiment. FIG. 4 is a block diagram showing the 411 configuration of the conventional device, and FIG. 5 is a diagram for explaining the operation of the conventional device. 4...Weighing conveyor, 5...Measuring device,
10...Weight sorting device,]1...Carry-in sensor, 12...AD converter, 13...
- Subtractor, 14...Zero correction value storage means, 15
. . . Timer circuit, 16 . . . Zero data accumulation storage means, 17 . . . f-minority determination means, 1
8...Debrightener, 19...Zero correction value updating means, 22...Determination means. Engraving of the drawings (no change in content) No. 4 No. 5 Procedural amendment basis (frog) May 16, 1990 1, Indication of the case 1990 Patent application No. 87273 2, Title of the invention Weight sorting device 3, Amendment Relationship with the case of a person who does
57) Anritsu Corporation Representative Shinji Sugai 4, Agent 141 Telephone 490-4516 Address 1-17-5 Osaki, Tokyo Parts Ward 6゜Contents of amendment

Claims (1)

[Scope of Claims] An article weight signal obtained by measuring the weight of an article carried into a conveyor with a weighing device together with the weight of the conveyor, and subtracting a zero correction value corresponding to the weight of the conveyor from the weighing signal. A weight sorting device that performs sorting determination of articles based on the weight sorting device, comprising: an AD converter that converts a weighing signal from the scale into weighing data; a zero correction value storage means that stores the zero correction value; non-load time detection means for detecting a non-load time from when the article is taken out from the conveyor until the next article starts being carried in; a subtraction means for subtracting a zero correction value obtained from the above; a non-load data storage means for storing non-load data from the AD converter or the subtraction means; a total time determining means for determining the total time, and when the total time determining means determines that the sum of the plurality of non-loading times has reached a predetermined time, the non-loading data stored in the non-loading data storage means during the predetermined time; an average value calculation means for calculating an average value of non-loaded data; and based on the average value calculated by the average value calculation means,
A weight sorting device comprising: zero correction value updating means for updating the zero correction value stored in the zero correction value storage means.