JPH03191833A - Rotating-type measuring method - Google Patents

Abstract

PURPOSE:To correct the error in centrifugal force and to make it possible to perform a highly accurate measurement by obtaining the errors in centrifugal forces under the initial state of a device and the reference-material mounted state. CONSTITUTION:A plurality of measuring means 12 (121 - 12n) which are turned around a rotary center 0 at an equal speed are provided in a device 10. Under the initial state wherein a material 20 is not mounted on the means 12 and the reference-material mounted state, the static fluctuation component of the output at the non-rotating state of the device 10, the output at the time of rotation at the specified speed and the errors in centrifugal force which is the vertical component of the generated force that is made to balance with the generated centrifugal force from those outputs are measured. During the rotation of the device 10 at a specified speed, the presence or absence of the mounting of the material 20 which is close to the weight of the reference material is judged. When the material 20 is mounted, the weight of the material 20 is operated from the output of the means 12, the static fluctuation component and the error in centrifugal force when the reference material is mounted. When the material is not mounted, the static fluctuation component is corrected from the output of the means 12 and the error in initial centrifugal force.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a weighing method using a rotary weighing device in which a rotating means rotates around a center of rotation, and in particular to a weighing method using a rotary weighing device in which a rotating means rotates around a center of rotation. related to correcting errors caused by

[Prior Art] Conventionally, as shown in FIG. 12, in a rotary weighing device, an article 4 is loaded on a weighing means 2, such as a load cell, coupled to a rotation center O, and the weighing means 2 is rotated. There is something to be measured. In such a rotary weighing device, when the weighing means 2 is bent and rotated by an angle θ due to the weight of the article, a force F1 that balances the centrifugal force F is required. This force F1 is generated as a horizontal component of the force F2 that occurs parallel to the horizontal beam 8 of the measuring means 2. Such force F2 is the resultant force of F and the force perpendicular to it, that is, the vertical component force F□, so
This vertical force F3 was applied upward to the measuring means 2, and prevented accurate measurement by the measuring means 2. As is clear from FIG. 12, this vertical component F3 has a magnitude of F tan θ. In addition, F is the distance r from the center of rotation O to the measuring means 2, - the total mass of the product 4 and the measuring means 2 is m1
If the rotation speed of the rotary weighing device is ■, then F=mv2/
It is r.

In order to eliminate the influence of F3,
Publication No. 55002 discloses that the above F3 is calculated by F tan θ and added to the output of the measuring means 2.

[Problem to be solved by the invention] However, in the above publication, F3 is simply determined.

It only describes that it is added to the output of the measuring means 2, but does not specifically describe how to remove Fat.

[Means for Solving the Problems] A first method of the present invention is a rotary weighing device having a weighing means that rotates at a constant speed around a predetermined center of rotation, in an initial state where no article is loaded on the weighing means. and a step of measuring the static fluctuation component which is the output of the measuring means when the rotary measuring device is in a non-rotating state, and a step of measuring the static fluctuation component which is the output of the measuring means when the rotary measuring device is in a non-rotating state, and a step in which the rotary measuring device is rotating at a predetermined speed in the above-mentioned initial state. Initial centrifugal force, which is the vertical component of the force generated to balance the centrifugal force generated during rotation of the one-rotation counterfeit device in its initial state, based on the output of the measuring means in the current state and the above-mentioned static variation. Based on the step of measuring the error and the output of the measuring means when the reference article is loaded on the measuring means and the rotary measuring device is rotating at a predetermined speed and the static variation, A step of determining a centrifugal force error when a reference article is loaded, which is a vertical component of the force generated to balance the centrifugal force generated during rotation of the rotary weighing device with a reference article loaded, and a predetermined speed of the rotary weighing device. a step of determining whether or not an article to be weighed having a weight close to the weight of the reference article is loaded in the rotating state; and when it is determined that an article to be weighed is loaded, The step of calculating the weight of the article to be weighed based on the output, static fluctuation, and centrifugal force error when loading the reference number of articles; and when it is determined that the article to be weighed is not loaded, the output of the weighing means and the initial centrifugation are and correcting the static variation based on the force error.

The invention of fJS2 includes the step of measuring an initial value variation which is the output of the weighing means when the rotary weighing device is in a non-rotating state with no article loaded on the weighing means; determining its true static weight value;
The output of the measuring means, the rotational speed of the rotary measuring device, the initial value variation, and the true static weight value of the measuring means in a measurement state in which an article to be weighed is loaded on the measuring means and the rotary measuring device is rotating. a step of calculating a centrifugal force error, which is a vertical component of the force generated by the rotary weighing device in balance with the centrifugal force generated during rotation of the rotary weighing device in a state in which an object to be weighed is loaded; and an output of the weighing means in the measuring state; and calculating the weight of the article to be weighed based on the calculated centrifugal force error.

A third aspect of the present invention is the step of measuring a static fluctuation amount which is the output of the measuring means when the rotary measuring device is in a non-rotating state in an initial state where no article is loaded on the measuring means;
Based on the weight of the reference article and the rotary weighing device cI) The rotational speed and the initial load of the weighing means are generated to balance the centrifugal force generated based on the rotation of the reference article loaded on the weighing means. a step of calculating centrifugal force error when loading a reference article, which is a vertical component of the force; and a step of calculating a centrifugal force error when loading a reference article, which is a vertical component of the force; the step of calculating the weight of the article to be weighed based on the output of, the static variation, and the centrifugal force error when loading the base number of articles.

It is something that you have.

[Function] According to the first invention, the centrifugal force error that occurs when the measuring means is rotated with the reference article loaded thereon is measured in advance, and the centrifugal force error that occurs when the measuring means is rotated with the reference article loaded thereon, and the centrifugal force error that occurs when the measuring means is rotated with the reference article loaded therein is measured, and the centrifugal force error is measured in advance. The output of the measuring means when the measuring means is rotated with an article loaded includes a centrifugal force error approximately equal to the centrifugal force error when a reference article is loaded, and an initial stationary fluctuation. Therefore, the true weighing value of the article to be weighed is determined based on the output of the 51 quantity means, the centrifugal force error, and the initial fluctuation. In addition, the initial variation changes over time. Therefore, the initial stationary fluctuation is corrected based on the output of the weighing means when no article to be weighed is loaded and the initial centrifugal force error. That is, the output of the weighing means when no article to be weighed is loaded is composed of an initial stationary variation and an initial centrifugal force error, and the initial centrifugal force error is a constant value. Therefore, the initial fluctuation can be updated to the current value by calculating y4 between the output of the weighing means when no article to be weighed is loaded and the initial centrifugal force error.

The second invention is to remove the initial stationary fluctuation from the output of the measuring means when the rotary measuring device is rotating, and to obtain the centrifugal force error based on this and the rotational speed. , the initial stationary variation is.

It includes the measured value of the measuring means and the fluctuation of the zero point, but there is a possibility that the measured value already includes an error. Therefore, the true weight of the weighing means itself is determined separately, and the weight of the article to be weighed and the weight of the weighing means itself is determined based on the true weight of the weighing means itself, the output of the weighing means, and the initial fluctuation. , and the centrifugal force error is calculated based on this and the rotational speed. Strictly speaking, the weight of the article to be weighed and the weighing means itself includes a centrifugal force error, but since the value is small, it does not have a large effect.

In the third invention, the centrifugal force error when loading the reference article is calculated based on the weight of the reference article, the initial variation, and the weight of the weighing means itself, and this is used to measure the true weight of the article to be weighed. are doing.

[Example] A first example is shown in FIGS. 1 to 9. This example is for a weighing machine in which the weight of the article to be weighed is close to the reference weight M. The present invention is implemented in a rotary weighing device 10 used in a device that only needs to be able to weigh with high precision near a reference weight M.

As shown in FIG. 7, this rotary weighing device H10 includes n weighing means 12. 12n to 12n. These measuring means 12.
to 12. , are weighing platforms 141 to 14n and load cells 16° to 16., which are coupled to these, respectively. , has . These measuring means 12° to 12n are
It is configured to be rotated at a predetermined constant speed in the six directions of arrows by a drive source (not shown). These measuring means 12. The unweighed articles 20 are sequentially supplied by the star wheel 18 to 12□, and the articles 20 according to the weighing method are
0 is conveyed to a transfer conveyor 24 by a star wheel 22. Note that the unweighed articles 20 supplied to the star wheel 18 are also conveyed by the conveyor 24, but the unweighed articles 20 are conveyed in synchronization with the rotation of the star wheel 18.
A screw conveyor 26 is also provided for feeding the zero. 28 is a guide. Also, star wheel 18
, the rotation of the rotary weighing device 10 and the star wheel 22,
The receipt of articles 20 is synchronized to ensure accurate delivery.

As shown in FIG. 8, each load cell 15. Analog weighing signals output from amplifiers 301 to 30n
After being amplified by analog switches 32 to 3
2n to an A/D converter 34, where it is converted into a digital measurement signal and supplied to the CPU 38 via an interface 36.

The CPU 18 operates according to a program stored in the memory 40, and operates each analog switch 321 to 32n and A/D based on the pulse signals Ta, RP, and TP from the pulse generator 42 and the command signal from the keyboard 44.
By controlling the D converter 34, each load cell 1
61 to 16. ．． The output signals are digitized and inputted to the measuring means 121 to 12. The main purpose is to remove the weight (initial load) and zero point fluctuations, and further remove centrifugal force errors to obtain the true weighing value of the article 20, and perform one sorting by comparing this with the reference weight. These screening results are displayed on the display 46.

An outline of the calculations that the CPU 38 performs to obtain the true weight value of the article 20 is as follows.

For example, the measuring means 12. When measuring the weight of the article 20 while rotating, the load cell 16 at that time
．． The output W is.

W = W true+ W tare+ W z −W
An error will occur. However, W true is the true weight of the article 20, and W t a r e is the true weight of the article 20. weight of,
W2 is the fluctuation of the zero point.

W error is the weight of the article 20, the weighing means 12. This is the vertical component of the force generated to balance the centrifugal force generated based on the weight of the centrifugal force (referred to as centrifugal force error). Note that tWarrior is negative because, as is clear from FIG. 12, it acts upward. From the above formula, W t
To find rue, from W, W t a r e and W2
All you have to do is subtract and add W error. Then, add W true and W L a r @ to the measuring means + 2
．． is stationary and the article 20 is not loaded, and these measured values (referred to as initial value fluctuations) are stored. Similarly, whether W error is to be stored or not, strictly speaking, this value varies depending on the weight of the article 20. However, as mentioned above, in this example, article 20 is of standard iM
Therefore, even if the centrifugal force error when an article having a reference weight M is loaded on the measuring means 12+ is used as W e r r o r, a large error will not occur. Therefore, The article having a reference weight M is weighed by means 12. The centrifugal force error (reference article loading hourly centrifugal force error) Werror is stored. Then, subtract Wt a r e + W z from W, and get W
By adding error', W t r u
Find e.

However, of +Wtare+W, W changes due to changes over time. Therefore, the metering means 12. 20 goods to
Is it necessary to perform so-called zero point adjustment when there is no load? The output Wo of the load cell 121 when the article 20 is not loaded and rotates once is W O = W tar! ＋ wz W error'
''. However, We,...,' is the centrifugal force error that occurs when the article 20 is not loaded on the weighing means 12. Therefore, W L a r e is subtracted from Wo, and W
A new zero point variation is obtained by adding "error", and this is used to calculate the true weight W t of the article 20 from now on.
Find rue. Therefore, when the weighing means 12 is in a stationary state and no article 20 is loaded, W t a
r e and W e r r Q r'' and memorize them.

In order to perform the above processing, the CPU 38.

As shown in FIG. 4, when the power is turned on, initialization is performed, a static 1-weighing command is given, and the static weighing flag S W F is set to 1 (step S2).

Then, at the end of the measurement, judge whether the r-frac WEGF is 1 or not.
Step S4 is repeated until Step S4 becomes Y'ES. At this time, each measuring stage 12. to 12. It is assumed that the vehicle is stopped and the article 20 is not loaded.

On the other hand, CP 038 interrupts the pulse generator 42 to generate the pulse signal Ta, and
The process shown in the figure is performed. That is, when an interrupt occurs as shown in FIG. 2, it is determined whether a dynamic weighing command has been given (step S6), but since the answer is NO, dynamic weighing is performed as shown in FIG. The timing pulse count control flag TPF used in step S8 is set to 0, and it is determined whether SWF is 1 (step S8).
1 bite). Since SWF is set to 1 first, step S
The answer of IO is YES. Next, the flag SSF, which is set to l when the load cell to be measured is specified.
If the answer is NO, the flag SSF is set to 1 (step 514), and each load cell 16. 1 when starting to specify +6n
It is determined whether flag R3F is set to 1 (step 515). If the answer is NO, flag RSF is set to 1 (step 518), and each analog switch 32. 32r1 to each load cell 16. Set the value of the counter SSC to 1 to specify from +6n to step 52.
0), the analog switch (in this case, analog switch 321) corresponding to the value of the counter SSC is closed (step 522). As a result, the load cell +6. The output of is supplied to the A/D converter 34. Following step S22, the flag WAITF, which is set to 1 when the analog switch is closed, is set to 1, and the flag WEIGF, which is set to 1 when the A/D conversion timing is reached, is set to 0 (step 524). Terminate the loading routine.

Next, when the pulse signal Ta is generated and the interrupt routine is executed, the process goes through step S6.8.10 and step S1
Since the answer is YES, it is determined whether the flag WEIGF is O (step 526).

This answer is N because the flag WEIGF is set to 0 first.
o, and then determine whether the flag WAITF is 1 (step 528).
Therefore, the answer is YES, and the time measurement counter WC
The value of the counter WC is incremented by 1 (step 530), and it is determined whether the value of the counter WC is equal to a predetermined value ql (step 532). If the answer is No, this interrupt routine is ended. Hereafter, each time the pulse signal Ta is generated,
Step S6.8.10.12.26.28.30.3
2 or the answer to step S32 is YES. Then, if the answer to step S32 is YES,
The value of the counter WC is set to 0, the flag WEIGF is set to 1, and the flag WAITF is set to 0, step S:14), and the interrupt routine is ended. The reason for waiting a certain period of time after closing the analog switch is that if A/D conversion is performed immediately after closing the analog switch, the A/D converter 34
This is because the output of the load cell supplied to the converter contains noise generated when the analog switch is closed, and the output of the load cell cannot be accurately A/D converted.

Next time an interrupt occurs, step S26 is performed in the same manner as above.
However, the answer to step S26 is to first set the flag W.
Since EIGF is set to 1, the answer is YES. Therefore, A
An A/D conversion command signal is given to the /D converter 34 to convert the output of the load cell 16i into a digital weighing signal Wi,
This is read (step 536). Note that the A/D converter 34 is capable of completing A/D conversion between the generation of the pulse signal Ta and the generation of the next pulse signal Ta. It is. The read digital weighing signal Wi is accumulated in the register ΣWi for accumulation, and the value of the counter WEC that counts the accumulated number is incremented by 1 (step S38.40), and the value of the counter WEC is increased by a predetermined number ml. If the answer is NO, the interrupt routine ends. Thereafter, each time the pulse signal Ta is generated, the digital weighing signal Wi is read, accumulated, and the cumulative number is counted.
When the count value becomes equal to ml (step S42
(the answer is YES), the value of register ΣWj is stored in register WIN
The value of the counter SSC is transferred to the register N (step 544), the flag WEGF is set to 1, and the value of the counter SSC is transferred to the register N.
Wi, counter WEC, and flag SSF are set to 0 (step 546), and the interrupt routine ends.

After the flag WEGF becomes 1 in this way, the answer to step S4 shown in FIG. 4 becomes YES.

Therefore, divide the stored value of register WINT by ml,
WI (in this case, the weight of the weighing means 12+) is calculated (step 548), and the flag WEGF is set to 0 (step 5SO), and the calculated WI is set in the initial load register specified by the value of register N ( Step 55
2), and increments the value of the counter CAC by 1, which counts the number of weighing means to which initial loads have been set (step 5).
54), determine whether the number is equal to the total number n of measuring means (step 556), and if the answer is NO, step S
Return to 4. Thereafter, the initial loads of other measuring means are set in the same manner. Therefore, in FIG. 3, step S1
If the answer to 6 is YES, that is, if the flag RSF is 1, then 1
Counter SSC to close the next analog switch
The value of is incremented by 1 (step 558), and step S22 is executed. When the initial loads of all the measuring means have been set in this way, the answer to step S56 becomes YES, the value of counter CAC is set to O, the flag RSF is set to 0, step 560), and this power-on routine is executed. finish. Note that if the answer to step S10 is NO, register ΣWi, force fy, t9WEc, WC, and SSC are set to 0, respectively (step 562), and flags SSF and RSF are set to 0.
? 0, and the SWF is set to 1 (step 564).

In this way, each measuring means 12. to 12. After the initial load has been set, when an instruction for zero point adjustment in a stationary state is given from the keyboard 44, the zero adjustment processing routine shown in FIG. 5(b) is executed. At this time as well, the pulse signal T
Each time a occurs, the interrupt routine shown in Figure 3 is executed, and each time the weighing end flag WEGF becomes 1, the load cell output (weighing A value obtained by accumulating m1 values (the sum of the initial load of the means and the zero point fluctuation) is stored.

In this routine, it is first determined whether the flag WEGF is 1 (step 566), and if the answer is NO, this routine ends. Also, the answer to step S66 is YES.
Then, the value stored in the register WINT at that time is ml
The average value W GSN of the combined value of the initial load of the measuring means specified by the register N and the zero point fluctuation is obtained (step 568). Then, the measurement end flag WEGF
is set to 0 (Step 570), and the stored value W8 of the initial load register specified by register N is subtracted from wasx to calculate the zero point variation WIN.Step 572), this zero point variation W2N is specified by register N. This routine is then stored in the zero point register (step 574). Thereafter, as long as a zero point adjustment instruction is similarly given, the zero point fluctuations for each measuring means are sequentially stored.

Furthermore, when an instruction for normal processing is given from the keyboard 44 in the stationary state, the normal processing routine shown in FIG. 5(a) is executed. In this case as well, the part of the interrupt routine shown in FIG. 3 is executed each time the pulse signal Ta is generated, and each time the weighing end flag WEGF becomes 1, the load cell indicated by the value of the register N is stored in the register WINT. output (if no article 20 is loaded on the weighing means, the combined value of the initial load of the weighing means and the zero point fluctuation,
When an article 20 is loaded on the weighing stage, a value obtained by accumulating m1 of the initial load of the weighing means, the zero point fluctuation, and the static weight of the article 20 is stored. In this routine, it is first determined whether the flag WEGF is 1 (step 576), and if the answer is NO, this routine ends. Further, if the answer to step S76 is YES, the value of the register WINT is divided by ml, and W a
Find s s (step 378), set the flag WEGF to O (step 5aO), and Wc5N at this time is
When the weighing means is loaded with no articles 20, it is the average value of the initial load of the weighing means and the zero point fluctuation, and when the weighing means is loaded with articles 20, the initial load of the weighing means and the zero point fluctuation are the average value. This is the average value with the static weight of the article 20.

The initial load W0 specified by the register N and the zero point fluctuation W2, 4 are subtracted from this W a s s to calculate WsN (step 582). This WSN indicates that the article 20 is not loaded on the weighing means. In this state, it is O, and when the article 20 is loaded on the measuring means, it is the static weight of the article 20. Then, it is determined whether an instruction to display this WSN has been given from the keyboard 44 (step 584).
, if the answer is No, this routine ends. If the answer to step S84 is YES, W□ is displayed on the display 46, and this routine is ended.

If we try to remove the influence of centrifugal force error from the weighing signal when the rotary weighing device 10 is rotating, we can calculate the centrifugal force error of the reference article when an article of reference weight M is loaded on each weighing means as described above. In addition, in order to correct the zero point fluctuation, it is necessary to calculate the initial centrifugal force error when no articles are loaded.In any case, each weighing means is rotating. In this case, it is desirable that each weighing signal be stable. Therefore, in this embodiment, measurement is performed when each measuring means reaches a point a near the star wheel 22 shown in FIG. 7. Therefore, each measuring means has a point a
The pulse generator 42 is configured to generate a pulse signal TP as shown in FIG. In addition, in order to determine which measuring means is the measuring means that has reached point a, the pulse generator 42 generates a pulse signal R every time a particular measuring means, for example 121, reaches point a.
It is also configured to generate P. Using these pulse signals TP and pulse signals RP, the cumulative value of the output of each measuring means by m is sequentially calculated by the portion shown in FIG. 2 among the interruptions caused by the pulse signal Ta.

That is, when an interrupt occurs, it is determined in step S6 whether a dynamic weighing command is given as shown in FIG. 2, and if the answer is YES, a flag SWF is set to 1 during static weighing. is set to 0 (step 562), and the pulse signal TP
It is determined whether the flag TPF, which is set to 1 when TP is supplied, is 1 (step 564). If the answer is No, it is determined whether the pulse signal TP is generated or not (step 564).
66), if the answer is YES, the flag TPF? 1 (step 568), then it is determined whether the pulse signal RP is generated (step 570). If the answer is YES, the measuring means reaching point a is 12 degrees, so each analog The value of the counter SSC specifying the switch and each load cell is set to 1 (step 572).
Then, the analog switch specified by the counter SSC (
In this case, analog switch 32. ), the flag WAITF is set to 1, and the flag WEIGF is set to 0.
, sets the counter WC to 0 (step 576), moves the value of the counter VC to the register CAD, sets the counter vC to 0 (step 578), and ends this routine. Note that the counter vC is for measuring the rotational speed of this rotary measuring device 10, and is not used in this embodiment, but will be used in the third embodiment described later.

Next, when an interrupt occurs, the value of the counter vC is incremented by 1 through steps S6, 62, and 64 (step S), and the following steps are performed.
Steps 526a, 28a, 30a, 32a, and 34a are executed, which corresponds to step S26 in the WIJ3 diagram.
．． This corresponds to 28.30.32.34, and as shown in FIG. 9, after closing the analog switch, it waits for nine pulse signals Ta.

When this is finished and an interrupt is triggered, step S6.62
．． 64.80.26a, step S:16a,
Steps 38a, 40a, 42a, 44a, and 46a are executed, which are also performed in steps S and 38.4 shown in FIG.
0.42.44.46, and as shown in FIG. 9, after waiting for nine pulse signals Ta, the cumulative value (WINT (memory value) and the value of register N indicating which measuring means is used. Such calculations are performed during a period when a dynamic weighing command is given.

Note that if the answer to step S66 is NO, the flag T
Set PF to 0 (step 582), then step S
Execute 80.

When such a calculation is being performed, the rotary weighing device 110 rotates without the article 20 being loaded on each weighing means, and when an initial centrifugal force error component storage command is given from the keyboard 44, the sixth As shown in figure (a), the flag W
It is determined whether EGF is 1 (step 584). If the answer is No, this routine ends. If the answer to step S84 is YES, the value stored in the register WINT is divided by m to obtain the total value W of the initial load W of the measuring means, the zero point variation W2, and the initial centrifugal force error ΔW8.

H is determined (step 586), and the flag WEGF is set to O (step 588). Then, according to the value of the register N, the initial load W of this measuring means! 8 and zero point fluctuation W2
．． 4 and subtracted from WGsH to obtain its absolute value ΔW□8 (step 590), which is accumulated and stored in the accumulation register ΣΔWIN (step 5
92), and the counter CAC that counts the number of measuring means for which the initial centrifugal force error has been calculated is incremented by 1 (step S!+4), and the count value becomes the total number of measuring means n.
If the answer is NO, this routine ends. Thereafter, when the cumulative value of the initial centrifugal force error of all the measuring means is similarly stored in the registers ΣΔW, H, the value of the counter CAC becomes n, and the answer to step S96 becomes YES. At this time, the register ΣΔW1.4 which is the cumulative value of the initial centrifugal force error of all the measuring means
The average initial centrifugal force error Δ of each weighing means is calculated by dividing the value of by n.
W1 is stored (step 598), counter CAC is set to O (step 5100), and this routine ends. In addition, in this routine, the average value of the initial centrifugal force error of each measuring means is calculated and this is commonly used as the initial centrifugal force error of each measuring means, but this is because the weight of each measuring means is approximately uniform. Because there is. If it is necessary to obtain the initial centrifugal force error of each measuring means with higher precision, the initial centrifugal force error may be measured multiple times for each measuring means and then averaged.

When a centrifugal force error component storage command is given from the keyboard 44 while the rotary weighing device 10 is operating with an article of reference weight M loaded on each weighing means, the sixth As shown in figure (b), the flag WEGF
is 1 (step S100), and if the answer is NO, this routine ends. Step S
If the answer to 100 is YES, the value stored in the register WINT is divided by m, and the initial load W8 of the measuring means, the zero point fluctuation WZ, the reference weight M, and the reference article loading hourly cardiac force error Δ are obtained.
Find the average value WGsN of those containing WXN (step S
102), set the flag WEGF to 0 (step S
104), and determines whether the value obtained by subtracting the initial load WIN specified by the register N and the zero point variation W2N from WGSN is smaller than the reference weight M and larger than a predetermined threshold M1 (step S106); If the answer is NO, it means that the user has forgotten to load the reference article onto the weighing means, and this routine ends. Also step 510
If the answer to question 6 is YES, the standard article is loaded, so the standard weight M and the initial load W specified by the register N are
IN and the zero point variation WAN are subtracted from WOs,4, and the absolute value thereof is determined as the reference article loading hourly mental force error ΔWXN (step S108), and this is accumulated and stored in the accumulation register ΣΔWXH (step S108). 110)
Then, the value of the counter CAC that counts the number of measuring means for which the centrifugal force error at the time of reference article loading has been calculated is incremented by 1 (step S112), and it is determined whether the value of this counter CAC is equal to n (step S112). S114), if the answer is NO, this routine is ended and the flag W is set as follows.
Each time EGF becomes 1, the above-described processing is performed.

Then, if the answer to step 5114 is YES, the register ΣΔWXN stores n cumulative values of centrifugal force errors at the time of loading the reference article, so this is divided by m.
Find the average value ΔWX of the centrifugal force error when loading the standard article,
This is memorized (step 5116), the counter CAC is set to 0 (step 5118), and this routine ends. By the way, this group? If it is desired to calculate with higher accuracy than the centrifugal force error when loading a P article, a plurality of reference article loading centrifugal force errors may be individually measured for each measuring means, and the average value thereof may be determined.

IT of each article 20 while each weighing means is rotating is performed as shown in FIG. 1 when a dynamic normal weighing command is given from the keyboard 44. That is, it is determined whether the flag WEGF is 1 (step S120).
, if the answer is No, this routine ends. If this judgment is YES, the value stored in the register WINT is divided by m, and the average value W of the initial load WITI of the measuring means, the zero point variation WZS, the weight of the article 20, and the centrifugal force error at the time of measurement is obtained. . Calculate s, 4. Step S122
), set the flag WEGF to 0 (step S124)
, and the initial load W! corresponding to this metering means specified by register N! 9 and the zero point fluctuation W and are subtracted from Was, 4 to find Wd□ (step S126), and it is determined whether this Wd□ is larger than the threshold value Ml (step S
28). If the answer is YES, the weighing means is loaded with the article 20, so the initial load WIN and the zero point fluctuation W2!11 are calculated as W. The true weight W dMN of the article 20 is calculated by subtracting it from sx and adding thereto the centrifugal force error ΔW when the reference article is loaded (step 5130). Then, using this weight W dMN, this Sorting process is performed to determine whether article 20 is a good item or a defective item (step 5132).
, exit this routine.

Further, if the answer to step 5128 is No, the article 20 is not loaded on the weighing means, so W, or the initial load W□8, the zero point variation W28, and the initial centrifugal force error ΔW□ are included. . Therefore, from w ass to initial load W
By subtracting +11 and adding the initial centrifugal force error ΔW, the latest zero point fluctuation W2 of this measuring means is obtained.
11 (step S134), and store this in register N.
(Step S1:
16), this routine ends. Therefore, the zero point fluctuation amount W in the subsequent step 5126. This latest zero point variation W2o is used.

In the first embodiment, the initial centrifugal force error and the centrifugal force error when loading a reference article were measured at the place where the rotary measuring bag N10 was used, and these were stored. It is stored in a factory or the like before t. That is, the initial centrifugal force error ΔW is calculated as follows: ΔW, = m−V”·tanθ/r. m is the initial load, which takes a constant value.

tanθ is also a constant value because m is a constant value, and r is also a constant value. Therefore, ΔWI is expressed as ΔW,=−V2. However, k is a proportionality constant. Generally, the speed value used by workers is the distance traveled per unit time V (m/
s) is the number of revolutions per unit time R (r, p, ■), so ΔW can be expressed as ΔW,=xfist R2. However, K is a proportionality constant. Therefore, the proportionality constant is determined by rotating the rotary weighing device 10 at a predetermined rotational speed R such that K=ΔW,/R2, and calculating the initial centrifugal force error Δ in the same manner as in the first embodiment.
W8 is measured and the proportionality constant K is determined based on the above formula.

This is done for various R, stored in correspondence with R, and by setting R, the corresponding K is read out and the initial load centrifugal force error ΔW1 is calculated.

Or, corresponding to each R, initial load centrifugal force error ΔW1
Alternatively, the initial load centrifugal force error ΔW may be read out by storing R and setting R.

The code and ΔW may be stored in correspondence with R, and ΔW1 or K may be read by setting the code.

The same applies to the centrifugal force error ΔWx when the reference article is loaded.

ΔWx is 1 to ΔWx =k 1 (Wl +M) ”・V”=
Since it is expressed as (W□10M)2・R2, set the reference weight M and rotation speed R,
In the same manner as in the first embodiment, the centrifugal force error ΔWX when the reference article is loaded is determined, and 1 is determined as x 1= (w+ +M)"・ft2/ΔWX. This is determined for various R and M. ,
It is stored, R and M are set at the time of use, Kl is read out, and ΔWX is calculated based on this Kl. Alternatively, instead of storing Kl, various ΔWX can be stored corresponding to /R and M.
By memorizing and setting R and M,
The corresponding ΔWx may be read out. In addition.

A code may be assigned to each of various pairs of R and M, and ΔWx may be read by setting this code. This eliminates the need for the user to measure and memorize the initial load centrifugal force error and reference article loading error each time. Moreover, it is convenient because the reference weight load hourly centrifugal force error and the initial load centrifugal force error can be read from the normally used rotation speed R. In the first and second examples, the centrifugal force error ΔWXN when the reference article was loaded was determined using the reference article having the reference weight M, but the reference article does not necessarily have to have the reference weight M. .

For example, select a suitable item from a group of items to be weighed, load it onto one of the weighing means with the rotary weighing device IO stopped, and measure the static weight M'. This M' is memorized and the rotary measuring device 10 is first rotated to obtain was,1, and from this and M', ΔWX
, 1 may be obtained, but since there is only one sample,
In order to improve reliability, it is preferable to perform the above-described process several times to obtain a plurality of ΔWXN, and to use the average value as the official ΔWXH.

In the third embodiment, the centrifugal force error during article loading is calculated based on the rotational speed of the rotary weighing device 10 and the measured value at that time. In other words, centrifugal force error Δ when loading articles
WXI, ΔWx+=k2-Wl/(2. However, W is the sum of the weight WX of the article and the initial load W of the weighing means, and C is the pulse generated while the weighing means moves a predetermined distance. The number of signals, ie a value inversely proportional to the speed V, R2 is a proportionality constant.

Therefore, the above equation can be expressed as ΔWXI=k 2 (Wx +w, )''/C2. WI can be measured and stored in the same manner as in the first embodiment, and C is the same as that used in the first embodiment. Pulse signal T
It can be measured using P or pulse signal RP. However, WX cannot be measured.

Weighing signal W at this time. In addition to Wx and W□, sN includes zero point fluctuations W2 and ΔWxt.
Even if ΔWx□ is obtained by subtracting I and Wl, that is, including ΔWX+ in addition to Wx, in place of W8, ΔWXI itself is too large = k 2 (Was
Find ΔWX□ by s - WZN) ”/C”. Note that when W□ is measured using each measuring means, there is a possibility that the measured value is not accurate due to deviations in the zero points of each load cell, zero drift of the measuring circuit, etc. Therefore, either measure the part corresponding to this initial load using another measuring means or calculate it logically to determine the initial load W! Find ＾, ΔW
If X□ is found, ΔWXI can be found with higher accuracy. In this way, when ΔWXf is determined, the weight W of the article 20 is determined as W X = W O5N − W s − W z + ΔW
Determine by I.

To obtain ΔWXI as described above, it is necessary to determine R2. R2 may be determined by numerical calculation, but the most practical method may be as follows.

That is, the initial load centrifugal force error ΔWf is determined in the same manner as in the first embodiment. At the same time, count the TP pulse signal or RP pulse signal, and count 0, which is proportional to the speed.
Find 1. The initial centrifugal force error ΔW1 at this time is ΔW t = k 2 ·W rA”/C−, so k2 is.

k2=ΔW,・C-”/　W　rs It is determined by

A flowchart for determining 2 in this manner is shown in Fig. 1θ. In this case as well, the interrupt routine shown in FIGS. 2 and 3 is executed every time the pulse signal Ta is generated. If the article is rotated without being loaded on each weighing means, each time the flag WEGF becomes 1, the weighing value including the initial load, zero point fluctuation, and initial load centrifugal force error of each weighing means is calculated. m cumulative values are obtained in register WINT. Therefore, first the flag WEGF is 1.
Step s 1so), the answer is NO.
If so, this routine ends. Step 5150
If the answer is YES, divide the value of WEGF by m,
An average value W of m measured values including the initial load of each measuring means, zero point fluctuation, and initial load centrifugal force error. H is determined (step 5152), and the flag WEGF is set to 0 (step S
154), and the value of the register CAU is set to C, which is accumulated and stored in the accumulation register ΣC (step S156). Here, the value of the register CAU is the value transferred from the counter vC as shown in step S78 of FIG. 2, and this VC is the value obtained by counting the pulse signal Ta as shown in step S80, and this count is This occurs during the period from when an analog switch is closed until the next analog switch is closed. That is,
The time from when one measuring means reaches position a shown in FIG. 7 until the next measuring means reaches position 1a is measured. That is, it is proportional to the speed of the metering means.

Following step 5156, initial load W! and the zero point variation W2 of this measuring means is subtracted from W, , and its absolute value is stored as the initial J4-centrifugal force error ΔW0 (step S158), and this is accumulated. ,
The accumulated value is stored in the register ΣΔWIN (step S160), and the value of the counter CAC that counts the number of measuring means that have measured the initial centrifugal force error ΔW is incremented by 1 (step S162). Determine whether the value is equal to the number n of all measuring means (step S16
4) If the answer is No, this routine ends. Thereafter, the initial centrifugal force error ΔW0 of each measuring means is accumulated in the same way, and when the number becomes n, the answer to step 5164 becomes YES, and the value stored in the register ΣΔWaN is divided by n, and the initial → ÷ centrifugal force error While determining ΔW□, the value of the register ΣC is divided by n to determine the average speed Ca (step S166), and ΔW, ・C1/W1A2
calculate k2 (step S168),
The counter CAC is set to 0 (step 5170), and this routine ends.

After setting 2 in this way, the article 2 is placed in each weighing means.
0 is loaded, the process shown in the flowchart in FIG. 11 is performed. In this case, too, the interrupt routine shown in FIGS. A value obtained by accumulating m measured values of the measuring means that have reached , is stored in the register WINT. Therefore, first, it is determined whether the flag WEGF is 1 or not in step S172).
, if the answer is NO, this routine ends. Step 5
If the answer to 172 is YES, the value of the register WINT is divided by m, and the average value Wao is obtained by subtracting the centrifugal force error from the sum of the weight of the article 20, the initial load, and the zero point fluctuation.
In step S174), flag WEGF is set to O.
(step S176), and register CA
The value of U is set to C (step S178).

This represents the speed of the metering means at point a. Then, k 2 (WtAx +w, , 4- (WIN+
Wzx))/c2 is calculated to calculate centrifugal force error ΔW□ (step s1ao), and from WosN to WIN and W! , 1, and add centrifugal force error ΔW
1. is added, and the true measurement value WdN from the measurement means is obtained (step 5182).
S, the article is loaded on the weighing means, so
A sorting process is performed using W and N (step S186
), exit this routine.

On the other hand, if the answer to step 5184 is No, no article 20 is loaded on the weighing means, so W(,5H
-W, N-W, , +ΔW, end.

[Effects of the Invention] As described above, according to the present invention, centrifugal force errors can be corrected, and measurement can be performed with very high precision. In particular, according to the first aspect of the invention, since fluctuations in the zero point can be corrected at any time, highly accurate measurement can be achieved. Further, according to the first invention, only articles whose weight is close to a specific reference weight can be weighed with high precision, but according to the second invention, centrifugal force errors can be corrected even for articles of arbitrary weight. I can do it. Further, according to the third aspect of the invention, centrifugal force errors can be automatically corrected by simply setting the rotational speed and reference weight.

[Brief explanation of drawings]

FIG. 1 is a flowchart of dynamic normal weighing of a first embodiment of the rotary weighing device according to the present invention, FIG. 2 is a flowchart of a part of the interrupt routine of the first embodiment, and FIG. 3 is the same. 4 is a flowchart of the rest of the interrupt routine of the first embodiment; FIG. 4 is a flowchart of the first embodiment when the power is turned on; FIG. 5 is a flowchart of the first embodiment in a standstill state; FIG. 7 is a mechanical configuration diagram of the first embodiment, FIG. 8 is a block diagram of the first embodiment, and FIG. 9 is a flowchart of the first embodiment during rotation. Fig. 10 is a flowchart for determining the proportionality constant of the third embodiment, Fig. 11 is a flowchart for dynamic measurement of the third embodiment, and Fig. 12 is a centrifugal force error diagram. FIG. 10...Rotary measuring device, 16. ~16n...
・Measuring means, ko8...CPU.

Claims (3)

[Claims] (1) In a rotary measuring device having a measuring means that rotates at a constant speed around a predetermined center of rotation, the rotary measuring device is in a non-rotating state in an initial state in which no article is loaded on the measuring means. a step of measuring the stationary fluctuation component which is the output of the measuring means when the output of the measuring means is in the initial state and the rotary measuring device is rotating at a predetermined speed; measuring an initial centrifugal force error, which is a vertical component of the force generated to balance the centrifugal force generated due to the rotation of the rotary measuring device in an initial state based on the variation; and the measuring means. of the rotary weighing device based on the output of the measuring means and the static variation when the reference article is loaded on the rotary weighing device and the rotary weighing device is rotating at the predetermined speed. a step of determining a centrifugal force error when the reference article is loaded, which is a vertical component of the force generated to balance the centrifugal force generated due to rotation in the reference article loading state; and at the predetermined speed of the rotary weighing device. a step of determining whether or not an article to be weighed having a weight close to the weight of the reference article is loaded thereon in a rotating state; and an output of the weighing means when it is determined that the article to be weighed is loaded. a step of calculating the weight of the article to be weighed based on the static variation and the centrifugal force error when loading the reference article; and an output of the weighing means when it is determined that the article to be weighed is not loaded. a step of correcting the static variation based on the initial centrifugal force error;
Rotary weighing method. (2) In a rotary measuring device having a measuring means that rotates at a constant speed around a predetermined center of rotation, the rotary measuring device is in a non-rotating state in an initial state in which no article is loaded on the measuring means. a step of measuring an initial value variation that is the output of the weighing means; a step of determining a true static weight value of the weighing means itself; and a step of measuring an article to be weighed when the weighing means is loaded with an article to be weighed and the rotary weighing device. The measured value of the rotary measuring device is based on the output of the measuring means in the measurement state in which the rotary measuring device is rotating, the rotational speed of the rotary measuring device, the initial value variation, and the true static weight value of the measuring device. a step of calculating a centrifugal force error which is a vertical component of the force generated to balance the centrifugal force generated during rotation in a loaded state, and an output of the measuring means in the measurement state and the calculated centrifugal force error; and calculating the weight of the article to be weighed based on the above. (3) In a rotary measuring device having a measuring means that rotates at a constant speed around a predetermined center of rotation, the rotary measuring device is in a non-rotating state in an initial state in which no article is loaded on the measuring means. measuring the stationary fluctuation component which is the output of the measuring means at the time; and measuring the reference article at the rotational speed based on the weight of the reference article, the rotational speed of the rotary weighing device, and the initial load of the measuring means. a step of calculating a centrifugal force error when the reference article is loaded, which is a vertical component of the force generated to balance the centrifugal force generated due to the rotation when the reference article is loaded on the measuring means; When an article to be weighed having a weight close to the weight of the article is loaded and the rotary weighing device is in a rotating state, the article to be weighed is calculated based on the output of the weighing means, the static variation, and the centrifugal force error when loading the reference article. A rotary weighing method comprising the step of calculating the weight of.