JPH037048B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a display device for an electronic scale.

In general, the display of highly sensitive electronic scales fluctuates greatly due to temporary disturbances such as minute vibrations, so conventionally, the display averages a large number of data sampled at predetermined time intervals and displays the value. A method was adopted to suppress the above-mentioned fluctuations. However, this method has the disadvantage that the response of the display to the load value actually placed on the electronic scale is very slow, which is a problem especially in operations such as weighing a fixed amount. Also,
For the measurer, in order to judge whether the displayed value has reached a stable state, it is necessary to wait while watching the display until the displayed value does not fluctuate for a certain period of time. It was becoming a considerable burden on the volume work.

The present invention has been made in view of the above, and automatically determines whether the measured value is fluctuating or stable, and in the fluctuating state, displays an average value based on a small number of sampling data in order to speed up the above-mentioned response.
Once the balance has reached a stable state, it will display the average value with the number of data sequentially increased, and when the average value calculation accuracy exceeds the precision of this electronic scale, it can display a message to confirm the stability display. The purpose is to provide a display device for various types of electronic scales.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

Digitally converted data from the electronic load measuring mechanism 1 is outputted to the control unit 3 via the input/output port 2 at minute intervals, for example, 0.2 seconds. The control unit 3 is composed of a microprocessor, and includes a central processing unit CPU, a read-only memory ROM, a random access memory RAM, and the like. The data introduced into the control unit 3 is stored in random access memory.
The data storage area of the random access memory RAM is provided with n+1 data storage areas, and each time the latest sampling data _d0 arrives, the oldest data is discarded. Data of d ₀ , d _{1 .} . . d _o is always stored. This random access memory RAM is used, in addition to the above-mentioned data storage section, to store various calculation results and as various registers, which will be described later. Read-only memory of control unit 3
A processing program, which will be described later, is written in the ROM. Also connected to the control unit 3 is a keyboard 4 used for inputting various constants etc. via the input/output port 2, and a display for displaying calculated values via the input/output port 2 and the interface circuit 5. device 6 is connected.

Next, we will discuss the effect. FIG. 2 is a flowchart showing a processing program according to an embodiment of the present invention. ST
1, the data in the random access memory RAM is shifted one by one, and the latest sampling data d ₀ is taken in ST2. In ST3, starting from the latest sampling data d ₀ , i pieces of data d ₀ , d ₁ ,...
Using d _i-1 , that is, the average value W ₀ of the latest i sampling data is calculated. In ST4, the latest average value W ₀ to the immediately preceding average value W ₁
is subtracted, and the difference δ ₀ between the latest average values is calculated.
In ST5, the absolute value of the latest difference δ ₀ and the absolute value of the immediately preceding difference δ ₁ are compared, and if the absolute value of the latest difference δ ₀ is large, the process proceeds to ST6, and if it is small, the process proceeds to ST7. In ST6, the decrease number register P is reset, and in ST7, the increase number register Q is reset. From ST6, the process proceeds to ST8, where it is determined whether the increase count register Q has reached a predetermined value a. If it has not reached the predetermined value a, the increase count register Q is incremented by one in ST10. From ST7
Proceed to ST9, and the decrease count register P is set to a predetermined value a.
It is determined whether the
In ST11, the count of decrease register P is incremented by one. The flow in ST5 to ST11 is a flow for determining whether the measured value is in a steady state or in a fluctuating state, and the meaning thereof will be described below based on the explanatory diagram shown in FIG. Figure 3 shows
For example, if n+1 of the data storage part in the random access memory RAM mentioned above is 10, then the average value
Set i to 3 to find W ₀ , and further ST8 and
This is an explanatory diagram when the predetermined value a in ST9 is set to 3, and as mentioned above, in ST5, the absolute value of the latest difference δ ₀ and the absolute value of the immediately preceding difference δ ₁ are compared, and the increase or decrease It is determined that the measured value has fluctuated or shifted to a stable state when the trend of For example, since the judgment is based on the average value obtained by averaging three values in a short time, changes in the state can be quickly detected. Note that ST12 and ST13 are provided to maintain the current state when 1δ ₀ 1=1δ ₁ 1. In addition, the use of absolute values when comparing the differences δ ₀ and δ ₁ makes it possible to perform the same discrimination when the measured values are increasing as shown in Figure 3, and conversely when the measured values are decreasing. It is for this purpose.
Returning to the flowchart in FIG. 2, if the value of register Q has reached a in ST8, that is, if it is determined that the measured value has shifted to a fluctuating state,
Proceeding from ST14 to ST15, the average value W ₀ calculated in ST3 using i (for example, 3) sampling data is displayed on the display 6. If the register Q has not reached a in ST8, the process advances to ST16 after ST10. If register P has not reached a in ST9, the above ST11 to ST14
Then, in ST14, the register N is reset to i, and in ST15, the number of sampling data is set to i.
The average value W ₀ calculated in ST3 is displayed. As described later, register N is provided to increase the number of sampling data for calculating the average value when it is determined that the measured value is in a stable state. If it is determined that it is in the state, it is reset to the initial averaged number i in ST14.
In ST8, register Q has not reached a.
That is, if it is not determined that the state has shifted to the fluctuating state, and if it is determined that the register P has reached a in ST9, that is, it is determined that the state has shifted to the stable state, the process proceeds to ST16, and in ST16, the register N is changed. It is determined whether the value, that is, the number of sampling data for calculating the average value has reached the maximum number of data collection N _nax . If the count has not been reached, register N is incremented by one in ST17 and the process advances to ST18. If the value of register N has reached the maximum number of data samples in ST16, the process proceeds to ST18 without incrementing register N by one. In ST18, the average value W' ₀ is calculated using the latest N data according to the value of the register N. ST16 to ST18 are a flow for calculating the average value by sequentially increasing the number of data for averaging when the measured values are stable up to the preset maximum number of data collection N _nax . Number of samples N _nax is the number of data for averaging N
This was established to prevent the number from increasing unnecessarily. Proceeding from ST18 to ST19, it is determined whether the number N of data for averaging has reached the preset guaranteed number K of data collection. If the data number N has reached the guaranteed data collection number K, R is calculated by calculating the following equation (1) in ST20.

R′=R·√/√ (1) Here, R is the permissible reading width of this electronic scale, that is, the accuracy of this electronic scale, which is statistically determined using a preset value. R' calculated by this equation (1) will be explained below.
FIG. 4 is a graph showing the relationship between the number of data samples n and measured values. In the figure, the stability width B is determined by the above R and the number of data samples n as ±B=±R・√...(2), and statistically speaking, the standard deviation of the population σ
This corresponds to a range of ±3σ. Therefore, if the locus of the response waveform of the measured value falls within this stability range B, it means that the measured value is accurate within the above-mentioned range R. Therefore, when the measured value is in a stable state, the number of data samples n is set in advance to K.
The response waveform of the measured value almost always falls within this stability range B.
A guaranteed number of data samples K is set, and the stability width at that point is set as B'.

±B'=±R・√...(3) Then, based on the stability width B' at guaranteed data collection number K, stable reading width at data collection number N
If we calculate R' backwards, from equation (2), R'=B'/√...(4) From (3) and (4), we get R'=R・√/√...(5). This R' becomes R'<R when the number of data samples N exceeds the guaranteed number of data samples K, and therefore, the electronic scale can be read in a range smaller than the statistically determined allowable reading width R. It has the meaning of being. Returning to the flowchart in Figure 2, R' obtained by ST20 is ST21
This is displayed to confirm that the currently displayed average value W′ ₀ is a stable display. In ST22, the average value W' ₀ of the N pieces of data obtained in ST18 is displayed. If the value of register N has not reached K in ST19, the process proceeds to ST22 without displaying the above-mentioned display confirming the stability display (displaying R'), which is the average value based on N data.
Display W′ ₀ .

In addition, the display to corroborate the stability display is configured so that when N reaches K from ST19 without calculating R', all or part of the display for the average value W ₀ blinks. Alternatively, for example, the unit symbol or decimal point on the display may be blinked, or a separate auxiliary display means may be provided to light up a lamp or to light up an "OK" or "GOOD" display. Good too.

Also, in ST20, input a constant k in advance and calculate the value of R' divided by k, SD=R'/K...(6), and the SD can be estimated as the standard deviation. Therefore, this SD may be displayed as a display to confirm stability display.

FIG. 5 shows an example of a display for checking stability display. Figure 5a shows an example in which the above-mentioned auxiliary display means 7 lights up the lamp or "OK", and Figure 5b shows the value of R'(N<
In the case of K, the value of R' (or R) is displayed on the bar display 8 provided as an auxiliary display means, and in c, the value of R' (or R) is similarly displayed on the auxiliary display. 9 shows an example configured for digital display. Note that this R'(R) may be the SD determined by the above-mentioned equation (6).

As explained above, according to the present invention, it is possible to constantly determine whether a measured value is in a fluctuating state or a stable state, and in a fluctuating state, the average value is displayed moment by moment using a small number of averaged values to improve responsiveness. When the balance is stabilized, the number of averaged items is increased one after another, the average value is calculated and displayed, and when the accuracy of the average value calculation exceeds the sensitivity of this electronic scale, the displayed value becomes stable. Since there is a display to confirm the fact, there is no need to keep watching the displayed value unlike the display device of conventional electronic scales, and the burden of weighing work can be reduced.

In addition, by displaying the stable reading width, it is possible to inform the operator that more precise and stable measurements are being taken, so that the operator can carry out weighing tasks with confidence. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the embodiment of the present invention, Fig. 2 is a flowchart showing its processing program, Fig. 3 is an explanatory diagram of the operation of the embodiment of the present invention, and Fig. 4
The figure is a characteristic diagram showing the relationship between the number of data samples, measured values, stability width, etc., and FIG. 5 is an embodiment of a display device with a stability display confirmation display according to the present invention. DESCRIPTION OF SYMBOLS 1...Electronic load measuring mechanism, 2...Input/output port, 3...Control unit, 6...Display device, 7...Auxiliary display means, 8...Bar display device, 9...Auxiliary display device.

Claims (1)

[Scope of Claims] 1. Data sampling means for sampling digitally converted data of the electronic load measuring mechanism at predetermined time intervals; and first data averaging means for calculating an average value based on a predetermined number of sampled data; stability determining means for determining whether a measured value is in a fluctuating state or a stable state from a time-series change in the average value by the first data averaging means; A second data averaging means that calculates an average value by sequentially increasing the number of data for each data sampling, and whether the accuracy of calculating the average value by the second data averaging means has improved over the accuracy of the electronic scale. The weighing value display device of the electronic scale includes a precision determining means for determining whether the accuracy has improved, and a stability display confirmation display means that lights up when the precision determining means determines that the stability has improved. A display of an electronic scale configured to display the average value obtained by the first data averaging means when the measured value is in a fluctuating state, and display the average value obtained by the second data averaging means when the measured value is stable, based on the determination result by Device. 2. The display device for an electronic scale according to claim 1, wherein the stability display confirmation display means is a blinking of the displayed value of the weighed value display device. 3. A display device for an electronic scale according to claim 1, wherein the stability display confirmation display means is a blinking of a unit symbol and a decimal point display section of the weighing value display device. 4. The display device for an electronic scale according to claim 1, wherein the stability display confirmation display means is lighting of an auxiliary display means of the weighed value display device. 5. The display device for an electronic scale according to claim 1, wherein the stability display confirmation display means is a lighting display of an auxiliary display device attached to the weighing value display device. 6. Claims characterized in that the precision determining means makes the determination based on whether the number of data for calculating the average value by the second data averaging means reaches a preset number. Section 1, Section 2
A display device for an electronic scale according to item 1, 3, 4, or 5. 7 When the number N of data for calculating the average value by the second data averaging means reaches the preset number K, perform the calculation shown below and display the result by the stability display confirmation display means. ,below
5. A display device for an electronic scale according to claim 4, wherein the display device for an electronic scale is characterized in that the value of R' is displayed on an auxiliary display means. R'=R・√/√ Here, R: Accuracy of the electronic scale R': Actual accuracy of the electronic scale when the number of data for calculating the average value is N