JPS62167417A - Electronic balance - Google Patents

Abstract

PURPOSE:To increase a response speed in loading and unloading and enable a stable weighing display to be conducted after a load becomes stationary by calculating the means value of (m) updated load data every sampling of the load data. CONSTITUTION:The load data digitally converted by the A/D converter of a load detector 1 are taken in a controller 2. Since an adding register (RAM) 23 in a stable condition has its contents multiplied by 1/p every time when a maximum number T of stored data is reached and successively stores sampling data d0, an aggregate mean value Do becomes the mean value of a number of the data and a displayed value becomes stable. The sampling data d0 are compared with the aggregate mean value Do and, since, only when the difference therebetween is larger than a prescribed value and the differences with the same polarity are present S times or more among M times, the data are judged to shift to a changing condition, the displayed value is not affected by disturbance or the like. When the data are judged to be in the changing condition, immediately the average Wo of (m) updated data is displayed as a weighed value. Thus, a response is quick and a stable weighing display can be conducted.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to electronic balances.

<Prior Art> In conventional electronic balances, when using an A-D converter whose accuracy is not very high due to disturbances, etc., in order to improve the stability of the measured and displayed values of the electronic balance, A data processing method is adopted in which, for example, 10 points of digital conversion data from the load detection section are collected and averaged, and the average value is displayed.

<Problems to be Solved by the Invention> The conventional data processing method as described above, that is, the method of simply averaging several pieces of data, does not significantly improve display stability, and as a practical matter, ± There is a fluctuation in the display of about 1 count, and if the number of averaged data is too large, the responsiveness of the display will decrease, making it difficult to provide highly reliable display values to the measurer. The reality is that it is not possible.

The present invention was made in view of the above, and aims to respond quickly when a load is placed or removed, and to obtain an extremely stable weighing display value after the load has stopped. The purpose of the present invention is to provide an electronic balance that can achieve the above-mentioned objectives while using various parts (A-D converter, CPU, etc.).

Means for Solving the Problems> The configuration of the present invention will be described below with reference to the basic conceptual diagram shown in FIG.

The data sampling means a samples the digitally converted data from the load detection section at a predetermined period. The first data averaging means C calculates the average value W□ of the latest mflMl (do, d+...dm-1) of the sampled data. The data stability determining means d calculates the above-mentioned average value Wo from at least m pieces of data (d
m, dm+1 + ...d2m-1) average value W
The difference is the preset fluctuation range ±
It is determined whether the data is in a stable state or not depending on whether or not it is within B.

When it is determined that the data is in a stable state, the latest sampling data dQ is added and stored in the addition register e, but the addition register e is stored in the addition register control means f.
It is controlled as follows. That is, the addition register control means f determines whether the number N of data added and stored in the addition register e reaches a preset T number, and in the case of NET, the above-mentioned data ct
.

When N = T, the contents of the addition register e and the number of addition data (N = T) are expressed as p (
After updating the contents of the addition register e by dividing by p (p is an integer of 2 or more), addition and storage of the above-mentioned data do is permitted.

The second data averaging means g divides the contents of the addition register e by the number N of data to be added to calculate a cumulative average value Do. The disturbance/fluctuation discrimination means compares the latest sampling data dO and the cumulative average value DO in a stable data state, and determines whether the difference is larger than a preset variation width ±b and has the same polarity. Only when a value appears eight times or more during M consecutive comparisons, it is determined that the data has transitioned to a fluctuating state, and the contents of the addition register e are cleared.

The display section i is configured to display the cumulative average value D+) as a measured value when the data is in a stable state, and the average value WO when the data is not in a stable state.

<Operation> Basic stability judgment of the load data is performed based on the difference between the data average values WO and Wl of m adjacent data, and when the load data is in a stable state, the cumulative average value is calculated from the contents of the addition register e. DO is calculated and displayed as a measured value. The stable state of addition register e is 11! As long as the maximum number of stored data T is reached, the contents will be reduced by 1/p (for example, 1/2) and the sampling data dO will be stored one after another. This will be the average value of the data, and the displayed value will be extremely stable. In addition, in this stable state, the sampling data dO is compared with the cumulative average value DO, and if the difference is larger than a predetermined value and S times in M mouths (for example, 8
It is determined that the data has transitioned from a stable state to a changing state only when a difference of the same polarity appears (5 times in a cycle). The DO, which is the average value of the data, continues to be displayed and is not affected by external disturbances. When it is determined that the data is in a fluctuating state, the average WO of the latest m pieces (for example, 3 pieces) is immediately displayed as the weighing value, so the displayed value shows a prompt response when loading or unloading a load, etc. Become.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.

The load detection unit 1 includes, in addition to a load sensor that generates an electric signal corresponding to the load on the plate la, an A-D converter that digitizes the electric signal according to a command from the control unit 2. . The load data digitized by this A-D converter is input into the control section 2.

The control unit 2 is composed of a microcomputer, which executes programs described later and controls internal and external peripheral devices.
PU21. ROM22 in which the program described below is written
．． It is equipped with a RAM 23 in which an area as an addition register, an area for storing sampling data, etc., which will be described later, are set.
A D command is issued to collect load data, and as described later, a measurement display value is determined and displayed on the display 3.

FIG. 3 is a flowchart showing a data processing program written in the ROM 22. Hereinafter, the operation of the embodiment of the present invention will be explained with reference to this diagram.

The digital conversion data from the load detection section 1 is taken into the control section 2 moment by moment at a predetermined minute cycle, but the RAM 23 has an area for storing up to nine pieces of data, for example, and the latest data dO The oldest data d8 is discarded every time d8 is sampled (STI, 5T2).

Every time data dQ is collected, the latest three data ct
, , , di ,' ct2 average value WO is calculated and stored in the RAM 23 (Sr1). When the stability flag described later is not set, that is, when it is determined that the data is not in a stable state until the data dQ is sampled, the average value WO and 1. H[l
3 data before il d3. Average value W of d4°d5
l, and the three previous data c+6°d7. d8 and the average value W2 are respectively compared, and the difference W□-W1. W
It is determined whether □-W2 is within a preset fluctuation width ±B (Sr1.Sr5, 5T6), difference WO
If either -Wl or w(, -w2 is not within the fluctuation range ±B, it is determined that the data is within the fluctuation range, that is, the load on the plate la is not stationary, and the latest three data ao
, at, and a2 is displayed on the display 3 as a measured value (Sr1, 5T9).

Both the difference WQ-Wl and WO-W2 have a fluctuation range ±
If it falls within B, it is determined that the data has entered a stable state, that is, the load on the plate la has stopped, and a stability flag is set (ST10).

At the beginning, when it is determined that this stable state has been reached,
As the content Σ of the addition register set in the RAM 23, store the sum of nine data dQ, dl-d3, and assign 9 to the area that stores the number N of data stored in the addition register. (STI 1.
STI 2). Next, the content Σ of the addition register is divided by the number of stored data N, and the cumulative average value Do (in this case aO
, al...d8) is determined and displayed on the display 3 (ST13, 5T14°5T9).

As long as the stable state continues, each time data dQ is sampled, the data dO is sequentially added and stored in the addition register to update its content Σ, and the value of the number of stored data N is counted by 1. Up,
The cumulative averaged number is increased sequentially and the DO is displayed (ST
16.5T13°5T14.5T9). However, if the number N of addition storage data in the addition register reaches 32,
After reducing the content Σ of the addition register to 1/2 and the value of the number of stored data N to 1/2, the sampled data dQ is added to the content Σ of the addition register, and N
is counted up by 1, and the cumulative average value DO is calculated and displayed on the display 3 (ST15゜5T17, 5T13, 5T
14.5T9). In other words, if the stable state continues, the displayed value will essentially be the average value of an extremely large number of data, and it will be stable to the extent that even if a sudden disturbance occurs, the displayed value will not be affected at all. become.

While the data is determined to be in a stable state, the following method can be used to determine whether data fluctuations are due to disturbances, etc.
Or it is determined whether it is an actual load change. That is, when in a stable state, each time data dO is sampled, the data dO is compared with the cumulative average value Do, and the difference dO-Do is determined within a preset variation range ±
b (for example, the width of ±1 count of the minimum display digit). If the polarity of the difference exceeds ±b, the counter S(+) is incremented by one count if the polarity of the difference is positive, and the counter S(-) is incremented by one count if the polarity is negative. If either the counter S (+) or 5 (-) is less than 5, with 8 consecutive comparisons as one interval, even if there is a fluctuation in the data, it is determined that this is due to disturbance etc. (+) or S
Only when any of the (-) values is 5 or more out of 8 comparisons, it is determined that the data has transitioned from a stable state to a fluctuating state (ST18, 5T19, 5T20, 5T21 5T22
．． 5T23, 5T24, 5T25), immediately turn off the stability flag, clear the contents Σ of the addition register and the number of stored items N to O, and switch the display to the average value WO of the three data (Sr1, Sr1, 5T9) .

Note that in a stable state, when the sampling data dQ shows a large change, Sr1. It is immediately determined by Sr6 that the stable state has been broken, and the average value WO of the three pieces of data is immediately displayed as the measured value.

<Effects of the Invention> As explained above, according to the present invention, load data is sampled every moment, the latest average value W0 of m1lli (for example, 31 [1i1) is calculated for each sampling, and the average value Compare Wo with the average value W1 of the same number of previous data to determine whether the data is stable. If the data is not in a stable state, the average value WO is displayed moment by moment to quickly respond to load fluctuations and to ensure stability. When in the state, the average value DO of a large number of data is displayed based on the contents of the addition register, and as long as the stable state continues, the contents are halved, for example, and then the average value DO is displayed. By storing the data tiO, the cumulative value of a very large number of data is actually stored, and the average value Do can be stored in a cheap CPU with limited RAM capacity.
Even if U is used, it will be extremely stable.

Also, when in a stable state, the sampling data c
to and the cumulative average value DO, and when a difference of the same polarity with a predetermined value or more appears more than M times in a row, it is determined that the state has shifted from a stable state to a fluctuating state.
If the digital data fluctuates due to disturbances, noise, etc., or due to the accuracy of the A-D converter, it is determined that a stable state continues, and the average value DO of a large number of data items will continue to be displayed. Therefore, even if data fluctuates due to such causes, the displayed value will not fluctuate.

[Brief explanation of drawings]

Figure 1 is a basic conceptual diagram showing the configuration of the present invention, Figure 2 is a block diagram showing the configuration of an embodiment of the present invention, and Figure 3 is the ROM.
22 is a flowchart showing a data processing program written in 22. 1-Load detection section 1a--Dish 2-Control section 3--Display device 2 L-CP
U22-...ROM23-RAM

Claims (1)

[Claims] A data sampling means samples the digitally converted data from the load detection section at a predetermined period, and the latest m pieces of sampled data (d_0, d_1, . . .
d_m_-_1), and a first data averaging means that calculates the average value W_0 of the average value W_0 of at least m previous m data (dm, d_m_+_1, . . .
Data stability determines whether the data is in a stable state by comparing it with the average value W_1 of d_2_m_-_1) and determining whether the difference is within a preset fluctuation width ±B. and the latest sampling data d_ when it is determined that the data is in a stable state.
Determines whether the addition register that adds and stores 0 and the number N of data added and stored in the addition register reach a preset T, and if it is less than T, allows the addition and storage of the above d_0. However, when the number has reached T, the contents of the addition register and the number of addition data (
N=T) by p (p is an integer of 2 or more) to update the contents of the addition register, and then permit addition storage of the d_0; Divide by the number N, cumulative average value D_0
A second data averaging means that calculates the latest sampling data d_0 and the cumulative average value D_0 in a stable data state, and determines that the difference is larger than a preset variation range ±b, and Disturbance/fluctuation determining means for determining that the data has transitioned to a fluctuating state and clearing the contents of the addition register only when the same polarity appears S or more times during M consecutive comparisons; An electronic balance configured to display the cumulative average value D_0 as a weighing value when the balance is in a stable state, and to display the average value W_0 as a weighing value otherwise.