JPH0769208B2 - Electronic balance - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic balance, and more particularly to an electronic balance provided with a so-called stability indicator for reporting that load data is stable.

<Prior Art> The stability indicator as described above has been used conventionally, but in general, when the fluctuation amount of load data sampled momentarily from the load detection unit is within a preset allowable width. It is lit.

The weighing display value is determined by averaging the load data every moment (simple averaging, digital filter processing, etc.), so the above-mentioned lighting condition of the stability indicator is qualitatively a condition for stabilizing the weighing display value. Although it is almost satisfied, in the conventional electronic balance, the stability indicator is not turned on only when the weighing display value does not change at all, and the weighing display value changes by one to several counts while the stability indicator is lighting. Sometimes.

<Problems to be Solved by the Invention> By the way, when mainly handling jewels such as diamond, even if the least significant digit of the weighing display value of the electronic balance is different by 1, the price is greatly affected. When a conventional electronic balance is used for such transactions, since the lighting of the stability indicator does not have a quantitative relationship with the amount of change in the weighing display value, it may change during lighting as described above. Therefore, there is a problem that it is difficult to determine at what point the display value should be read.

An object of the present invention is to provide an electronic balance capable of lighting a stability indicator while guaranteeing that the weighing display value remains unchanged.

<Means for Solving Problems> A configuration for achieving the above object will be described with reference to the basic conceptual diagram shown in FIG.
The load value is displayed based on the data averaging means d which takes in the digital conversion data D from the data every moment and performs the averaging processing by using the plurality of data, and the data M processed by the data averaging means b. In the balance equipped with the weighing value display means c, the first stability determination means d for determining the stability of the data D from the load detection part a and the determination result by the first stability determination means d are unstable. The data M after being processed by the data averaging means b at the time of stable transition from the above is rounded to a reference value R by rounding it to a numerical value that is an integral multiple of the value corresponding to the minimum display unit by the weighing and displaying means c, and The data M after being processed by the data processing means b while the above state continues is stable depending on whether or not the data M is within the fluctuation width ε corresponding to ± 1/2 of the minimum display unit with respect to the reference value R. / Non-cheap It is characterized in that it is provided with a second stability determining means e for determining whether the temperature is constant and a stability indicator f that is turned on only when the determination result by the second stability determining means e is stable.

<Operation> The second stability determining means e determines the reference value R based on the data M at the time when the first stability determining means d determines that the data D has been stably changed, and the stability of the data D continues. During this period, the stability indicator f is turned on only when the subsequent data M is within the predetermined fluctuation range ε with respect to the reference value R. Here, the reference value R is obtained by rounding the data M into a numerical value that is an integral multiple of the value corresponding to the minimum display unit by the weighing display means c, and the fluctuation range ε is also ± 1/2 of the minimum display unit. Since the width is equivalent to, the fact that the data M is within ε with respect to the reference value R does not cause a change in the minimum display unit in the display value by the weighing display means c. In other words, it means that there is no change, and it can be guaranteed that there is no change in the measured display value when the stability indicator f is on.

<Examples> Examples of the present invention will be described below with reference to the drawings.

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

The load detection unit 1 has a built-in load sensor, an A-D converter and the like, and can output digital data corresponding to the load on the plate 11. This data is taken into the data processing unit 2 every predetermined minute time.

The data processing unit 2 is composed of a microcomputer including a CPU 21, a ROM 22, a RAM 23 and the like. A program to be described later is written in the ROM 22, and an area for storing the time-series data {X _n } from the load detection unit 1 and the time-series data {Y {after the digital filter processing described below} are stored in the RAM 23. An area for storing _n }, an area as a counter c, and the like are set.

A display device 3 for digitally displaying the measured value is connected to the data processing unit 2, and a stability indicator 31 is attached to the display device 3.

FIG. 3 is a flow chart showing a program written in the ROM 22. The operation will be described below with reference to this figure.

Here, the subscript _n in each time series data {X _n }, {Y _n }
The newest data is indicated by, and
It is supposed to become older in the order of _n-1 , _n-2 ....

At the same time as the program starts, all the time-series data {X _n }, {Y _n } in the RAM 23 are cleared and the contents of the counter c are also reset to 0 (ST1). Every time the data X _n from the load detection unit 1 is collected, digital filter processing is performed (ST2, ST3). This digital filter processing is executed by calculating the following expression (1).

Every time this process is performed, the counter c is incremented by one, but when the counter c reaches 32, it is not incremented (ST4, ST5).

When the counter c has not reached 32, it is displayed on the display device 3 according to the value of the counter c by the following process using the time-series data {Y _n } obtained by the digital filter process. The power value W to be determined is determined.

That is, when the value of the counter c is less than 8, (ST
6, ST7), the number of time series data% {Y _n } obtained by digital filtering is less than 8, so only the latest data Y _n is used to convert to the load value by multiplying the span coefficient. (ST8), and the value W is displayed on the display 3 (ST11). If the value of the counter c is 8 or more and less than 16 (ST6, ST7), the latest eight pieces of data Y _n , Y _n-1 ,
……, the mean value _n of Y _n-7 , that is, Is calculated, the value _n is converted into a load value (ST9), and the weight value W is displayed on the display 3 (ST11). Further, if the value of the counter c is 16 or more and less than 32 (ST6), the average value _{n 1 of} the latest 16 pieces of data Y _n , Y _n-1 , ..., Y _n-15 , that is, Is calculated, and the value _n is converted to the load value in the same way (ST1
0), it is displayed on the indicator 3 as the weight value W (ST11).

When the value of the counter c reaches 32, the latest 32 fluctuation widths of the time series data {Y _n }, that is, _Max {Y _n , Y _n-1 , ... Y _n-31 }. It is determined whether or not the value of −M _in {Y _n , Y _n-1 , ... Y _n-31 } is within 64, for example (ST12), and the first stability determination is performed. In this example, 32 of the value of the digital conversion data X _i from the load detection unit 1 and the value of the data Y _i after the digital filter processing, 32 is the minimum display unit of the weighing display value on the display device 3, that is, the least significant digit. It shall correspond to 1. The fluctuation range of Y _{n to} Y _{n -31} is 64
If it exceeds, it is considered that the first stability determination result is unstable, and the value of the counter c is reset to 0, and the data Y _i obtained up to that time obtained by the digital filtering process is reset.
Clear all (ST13). Then, the average value _n of the latest four X _n , X _n-1 , ... X _n-3 of the data X _i from the load detection unit 1
Is calculated, and the value is converted into a load value and displayed as the measured value W on the display 3 (ST14, ST1). Further, if a flag described later is ON, it is turned OFF (ST15).

If the first stability determination result in ST12 is stable, 32 pieces of data Y _n , Y _n−1 , ...
… The average value of Y _n-31 , that is, Is calculated (ST16). Then, the flag is judged to be ON / OFF (ST17), and if it is OFF, it is regarded as the first routine after the first stability judgment result has changed from unstable to stable, and ST
The average value _n of the 32 data obtained in 16 is rounded as described later, and the rounded value is stored in the RAM 23 as the reference value R (ST18) and the flag is turned ON (ST19). Also, this _n is converted into a load value and displayed on the display unit 3 (ST2
1) Turn on the stability indicator 31 (ST22).

The method of obtaining the reference value R described above is as follows.

That is, [X] is set in the form of R = 32 × [ _n / 32] (5) as a Gaussian symbol representing the maximum integer not exceeding x. That is, _n is rounded to a value that is an integer multiple of the value corresponding to the minimum unit of the measurement display value, and this is rounded to the reference value R
And

After determining this reference value R, when the first stability determination result continues to be stable, the average value _n obtained in ST16 is compared with the reference value R every time the data X _n is sampled. It is determined whether or not it is within the preset allowable fluctuation width ε, that is, the second stability determination (ST17, ST2
0). This fluctuation width ε is set to ± 1/2 of the minimum display unit on the display unit 3, that is, ± 16 when the data value 32 corresponds to the least significant digit 1 of the weighing display value as described above. It

That is, in ST20, it is determined whether or not | _n− R | <16 (6) is satisfied, and if this expression (5) is satisfied, the process proceeds to ST21 and ST22 and a stable data is obtained. 32
The display of the weighing value W based on the average value _n of the individual pieces and the lighting of the stability indicator 31 are continued. Here, satisfying the expression (6) means that the measured value W has been reached since the reference value R was determined.
Means that the least significant digit does not fluctuate by ± 0.5 or more, and the reference value R is a value rounded to an integer multiple of the value corresponding to the minimum display unit as shown in equation (5). ,
When the stability indicator 31 is continuously lit, the displayed value is completely unchanged. Here, when the reference value R is not rounded as described above and _n itself is used, if l is an integer and, for example, R = _n = 32 × l + 7 ... 7, then _n = 32 × When it becomes l + 18 (8), | R− _n | = 11 <16 (9), and the display value W may change by 1 point due to rounding while the stability indicator 31 is lit. By determining the reference value R by rounding _n as in equation (5), R is determined at the time of _n shown in equation (7) (in this case, R = 32 × l), and then (8) When _n as shown in the equation is obtained, | R− _n | = 18 and the equation (6) is not satisfied, and the stability indicator 31 is turned off. While the stability indicator 31 is on, The display value W can be completely unchanged.

Even when the reference value R is determined and the first stability determination result is also stable, if it is determined in ST20 that expression (5) is not satisfied, the flag is turned off (ST23) and the counter c is set.
Value is set to 24, and the old 8 of the time series {Y _n } after digital filtering are cleared (ST24) and ST10
Proceeding to, the measured value W is determined by the average value _n based on the equation (3) with 16 data, and the stability indicator 31
Is erased. That is, the first stability determination result is stable,
In the conventional electronic balance, even if the stability indicator 31 is lit, the stability indicator 31 is not lit if there is a possibility that the displayed value may change, but the time series data {Y _n } Leaves a part of it,
Used for determination of the measured value W. As a result, the stable weighing value W, in which the data is almost stable and the stability indicator 31 is conventionally turned on, does not suddenly change due to the destruction of the digital filter.

Also, changing the value of the counter c to 24 means that
When the first stability determination result is stable at the time of collecting the data X _n after the rotation, the process proceeds to ST16, ST17, ST18 and below to determine the reference value R again, and thereafter, the stability indicator 31 is turned on. It shows that there is something that can happen.

In the above examples, in determining the display value,
In fact determined by the form of the display value × 2 ^m 3 equation of _n the _(n) for time linear correction, to m bit right shift, but it is to obtain the displayed value by adding the carry, F _(n) If the coefficient of the first-order term which is the main term of is used, the second-order and third-order terms are small, so that 32 or the like of X _n or Y _n always corresponds to the least significant digit 1 of the displayed value.

Further, in the above embodiment, when the first stability determination result continues to be stable and the second stability determination result becomes unstable when the reference value R is set, it is set as c = 24. The processing using part of the digital filter processing data up to (24) was continued, but in this case, the value of c, that is, the number of data to continue to use, is arbitrary, and all (32) are used. You can also do it.

<Effects of the Invention> As described above, according to the present invention, when the determination result by the first stability determining unit is stable, the data after the processing by the data averaging unit at that time is displayed in the minimum display unit. To a reference value R by rounding to a value that is an integer multiple of the value corresponding to, while the determination result by the first stability determining means continues to be stable, the reference value R is processed by the data averaging means. It is determined whether or not the subsequent data is within the allowable fluctuation width ε that is within ± 1/2 of the minimum display unit (second stability determination means), and the stability indicator is turned on only when it is within the allowable range. Therefore, the stability indicator is surely lit only when the measured display value W is completely unchanged, and the definition of “stable” can be clarified. Heaven used for trading In like, it is possible to provide a display convincing both against trafficking both.

In this sense, the present invention can be applied not only to electronic balances, but also to devices that display a predetermined physical quantity by averaging processing based on time series data.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram showing the configuration of the present invention, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a flowchart showing a program written in the ROM 22. 1 …… Load detection unit 2 …… Data processing unit 21 …… CPU 22 …… ROM 23 …… RAM 3 …… Display unit 31 …… Stability indicator

Claims (4)

[Claims] 1. A data averaging means for taking in digitally converted data from a load detecting section every moment and averaging processing using a plurality of the data, and data based on the data processed by the data averaging means. In a balance equipped with a weighing value display means for displaying a load value, a first stability determination means for determining the stability / unstableness of the data from the load detection section and a determination result by the first stability determination means are not The data after processing by the data averaging means at the time of stable to stable transition is rounded to a numerical value that is an integer multiple of the value corresponding to the minimum display unit by the weighing value display means, and is used as a reference value. Whether the data after processing by the data averaging means during the continuous state is within the fluctuation range equivalent to ± 1/2 of the minimum display unit with respect to the reference value A second stability determination means for determining the stability / non-stability in either determination result by the second stability determination means is characterized by having a stable indicator lights only when it is stable, electronic balance. 2. When the determination result of the first stability determining means turns unstable after the setting of the reference value, the stability indicator is turned off and the reference value is cleared. The electronic balance according to claim 1. 3. The data averaging means is a digital filter, and when the discrimination result by the first stability discriminating means changes from stable to unstable, the processing result up to that time by the digital filter is cleared. Then, when the determination result by the first stability determination means is stable and the determination result by the second stability determination means is unstable, the processing of the digital filter is started. The electronic balance according to claim 1 or 2, wherein the electronic balance is configured to be continuously performed. 4. When the data averaging means is a digital filter and the discrimination result by the first stability discriminating means changes from stable to unstable, the processing result up to that time by the digital filter is cleared. Then, the processing is newly started, and when the determination result by the first stability determination means is stable and the determination result by the second stability determination means is unstable, it is determined by the digital filter. The electronic balance according to claim 1 or 2, wherein the processing is continued by using a part of the processing results up to the above.