JPH0546354A - Numerical data display apparatus - Google Patents

Abstract

PURPOSE:To decrease a variation of a display position of a decimal point by executing a fuzzy inference of the display position of the decimal point, based on numerical data from a data arithmetic part, and displaying the decimal point and the corresponding numerical data in an inference position. CONSTITUTION:An input circuit 2 measures a period of an input pulse corresponding to a rotation given from an encoder, etc., and a data arithmetic part 3 calculates an inverse number of the measured period and calculates revolution speed data being numerical data. A calculating part 7 in an inference part 4 calculates a degree of fluctuation by deriving a ratio of the present and the previous revolution speed data, and a decimal point position inference part 8 inputs the revolution speed data from the data arithmetic part 3 and the degree of fluctuation from the calculating part 7, executes a fuzzy inference, based on a membership function and a fuzzy rule, and outputs a decimal point position to be displayed to a display data working part 5. In such a way, in a steady state that the numerical data is scarcely fluctuated, a variation of a display position of a decimal point is decreased and an easily visible display can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for displaying numerical data, such as a counter or a tachometer,
More specifically, it relates to a device that displays numerical data including a decimal point in a plurality of digits.

[0002]

2. Description of the Related Art A device of this type, for example, a conventional tachometer is shown in the schematic block diagram of FIG. In the figure, 2 is an input circuit for measuring the cycle of an input pulse from an encoder or the like (not shown), 3 is a data operation unit for calculating the reciprocal of the measured cycle to calculate rotation speed data as numerical data, and 10 is On the basis of the calculated rotation speed data, for example, the display digit judging unit 5 for judging the decimal point position according to the flowchart of FIG. 8 is processing for displaying the decimal point and the corresponding rotation speed data as the display data at the judged position. The display data processing unit 6 is a display unit for displaying the rotation speed data in four digits including a decimal point.

In the display digit judging section 10, as shown in the flow chart of FIG.
When the value exceeds, the decimal point position changes from 0.000 to 00.00
However, even if the rotation speed data drops to 9 or 8, the decimal point position does not change, and when it drops to 7 or less, it changes from 00.00 to 0.000. Have. The same applies to other decimal point positions, and the hysteresis is 7 to 1
The sections are 0, 80-100, 900-1000.

[0004]

However, in such a tachometer, when the rotation speed data takes a value in the hysteresis interval and is stable, for example, the rotation speed data is between 6 and 11. In the steady state, the decimal point position changes frequently between 0.000 and 00.00, which is very difficult to see.

The present invention has been made in view of the above points, and it is an object of the present invention to reduce the change in the display position of the decimal point and make the display easy to see in a steady state where the numerical data is stable. To do.

[0006]

In order to achieve the above object, the present invention is configured as follows.

That is, the present invention is a numerical data display device having a display unit for displaying variable numerical data with a plurality of digits including a decimal point, and based on the numerical data,
An inference unit for fuzzy inferring the display position of the decimal point is provided, and the decimal point and the numerical data corresponding to the decimal point position are displayed on the inferred display position on the display unit.

[0008]

According to the above construction, since the display position of the decimal point is fuzzy inferred based on the numerical data, the display position of the decimal point is changed even if the numerical data takes the value in the hysteresis section, as in the conventional example having a hysteresis characteristic. It does not change frequently and become difficult to see.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram of a tachometer according to one embodiment of the present invention. The portion corresponding to the conventional example of FIG.
The same reference numerals are attached.

The tachometer 1 of this embodiment has an input circuit 2 for measuring the cycle of an input pulse corresponding to the rotation given by an encoder (not shown), and a rotation as numerical data by calculating the reciprocal of the measured cycle. The data calculation unit 3 for calculating the numerical data, the inference unit 4 for fuzzy inference of the display position of the decimal point based on the rotational speed data as described later, and the decimal point and the corresponding rotational speed data at the inferred position. The display data processing unit 5 performs processing for displaying as display data, and the display unit 6 that displays the rotation speed data as four-digit display data including a decimal point,
The input circuit 2, the data calculation unit 3, the display data processing unit 5, and the display unit 6 are the same as in the conventional example of FIG.

The inference unit 4 which fuzzy infers an appropriate display position of the decimal point based on the rotation speed data calculates the degree of variation by obtaining the ratio between the current rotation speed data and the previous rotation speed data. 7 and a decimal point position inference unit 8 which fuzzy infers an appropriate decimal point display position based on the rotation speed data and the degree of variation from the calculation unit 7.

In the decimal point position inference unit 8, the data operation unit 3
The rotation speed data (hereinafter, also referred to as “dsp”) and the degree of fluctuation from the calculation unit 7 (hereinafter, also referred to as “pro”) are input, and fuzzy inference is performed based on the membership function and the fuzzy rule. The decimal point position to be displayed (hereinafter, also referred to as “pos”) is output to the display data processing unit 5.

FIG. 2A shows the membership function of the rotation speed data (dsp) which is an input variable of the decimal point position inference unit 8 and has four labels NB, NS, PS and PB.

In FIG. 2B, the decimal point position inference unit 8 is also shown.
The membership function of the degree of variation (pro) that is the input variable of NS, NM, NS, ZRB, ZRS,
It has eight labels of PS, PM and PB.

On the other hand, as shown in FIG. 3, the decimal point position (pos) to be displayed, which is an output variable, is ZR, NB,
It has five labels, NS, PS and PB, and corresponding membership function values.

In this embodiment, when there is almost no fluctuation in the rotation speed data or when there is a large fluctuation in the rotation speed data, which is considered to be due to noise or the like, the display position of the decimal point is not moved and the rotation speed is changed. When there is fluctuation in the data, the display position of the decimal point is moved according to the size of the rotation speed data.

That is, in this embodiment, the display position of the decimal point is inferred according to the following fuzzy rules shown in FIG.

The rotation speed data is very large (dsp =
PB), if there is a change in the rotation speed data from the previous rotation speed data (pro = NSorPS), the decimal point display position is set to 0000. (Pos = PB).

The rotation speed data is large (dsp = P
S) If there is a change in the rotation speed data from the previous rotation speed data (pro = NSorPS), the decimal point display position is set to 000.0 (pos = PS).

The rotation speed data is small (dsp = N
S) If there is a change in the rotation speed data from the previous rotation speed data (pro = NMorPM), the decimal point display position is set to 00.00 (pos = NS).

The rotation speed data is very small (dsp =
NB), if there is a change in the rotation speed data from the previous rotation speed data (pro = NMorPM), the decimal point display position is set to 0.000 (pos = NB).

Regardless of the size of the rotation speed data (ds
p = PBorPSorNSorNB), if there is almost no change in the rotation speed data from the previous rotation speed data (p
ro = ZRBorZRS), the display position of the decimal point is not moved (pos = ZR).

Regardless of the size of the rotation speed data (ds
p = PBorPSorNSorNB), if the fluctuation of the rotation speed data from the previous rotation speed data is extremely large (pro = PBorNB), the display position of the decimal point is not moved (pos = ZR).

In the decimal point position inference unit 8, given the rotation speed data (dsp) and the degree of variation (pro), the matching degree of the input variable of each label is calculated in the corresponding rule of the above fuzzy rules. Then, the smallest value is selected as the fitness of the input variable for each rule (MIN operation).

Next, the fitness of each input variable in each of the above rules is multiplied by the membership function value of each corresponding output variable label in FIG. 3, and the decimal point position is output as the label of the maximum value of these multiplied values. It That is, in this embodiment, the display position of the decimal point is obtained by the height method.

After the display position of the decimal point is inferred in this manner, the rotation speed data from the data calculation unit 3 is converted into the display data processing unit corresponding to the inferred decimal point position as in the conventional example. It is processed in 5, and is displayed on the display unit 6 in four digits including a decimal point.

In this way, since the display position of the decimal point is fuzzy inferred based on the rotational speed data, the decimal point position does not change frequently as in the conventional case in a steady state where the rotational speed data hardly changes. ,Also,
When the rotation speed data fluctuates, the decimal point position is moved to an appropriate position according to the size of the rotation speed data.

Further, when the rotational speed data changes abruptly due to the influence of noise or the like, the decimal point position does not move unlike the conventional example. If the rotation speed data suddenly fluctuates due to the influence of noise or the like, the previous data may be displayed as it is, and erroneous rotation speed data due to the influence of noise or the like may not be displayed. ..

As another embodiment of the present invention, FIG.
As shown in (A) and (B), the rotation speed data (ds
Even if the membership function of the degree of variation (pro) is changed according to the magnitude of p) and the display position of the decimal point is inferred based on the fuzzy rules shown in FIGS. 6 (A) and 6 (B). Good. That is, FIG. 5A shows the membership function of the degree of fluctuation (pro1) when the rotation speed data (dsp) is large or very large, and N
It has five labels B, NS, ZR, PS and PB, and FIG. 5B shows the membership function of the degree of fluctuation (pro2) when the rotation speed data (dsp) is small or very small. , NB, NS, ZR, PS, P
It has five labels of B.

In this embodiment, the membership function of the rotation speed data (dsp) and the output variable (pos), and other configurations are the same as those in the above embodiment.

In the above-mentioned embodiment, the description has been made by applying it to the tachometer, but the present invention is not limited to the tachometer.
Of course, it can be similarly applied to a counter, a timer, and other devices that display numerical data.

[0033]

As described above, according to the present invention, since the display position of the decimal point is fuzzy inferred based on the numerical data, the decimal point is displayed in a steady state where there is almost no fluctuation in the numerical data as in the conventional example. The position does not change frequently and becomes difficult to see, and the decimal point is displayed at the proper position according to the numerical data.

[Brief description of drawings]

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

FIG. 2 is a diagram showing membership functions of input variables (dsp) and (pro).

FIG. 3 is a diagram showing a membership function of an output variable (pos).

FIG. 4 is a diagram showing a fuzzy rule.

FIG. 5 is a diagram showing a membership function of an input variable (pro) according to another embodiment.

FIG. 6 is a diagram showing a fuzzy rule according to another embodiment.

FIG. 7 is a block diagram of a conventional example.

FIG. 8 is a flowchart for explaining the operation of the conventional example.

[Explanation of symbols]

 1 tachometer 2 input circuit 3 data calculation unit 4 inference unit 6 display unit

Claims (1)

[Claims] 1. A numerical data display device comprising a display unit for displaying variable numerical data in a plurality of digits including a decimal point, and an inference unit for fuzzy inferring a decimal point display position based on the numerical data. A numerical data display device, which displays a decimal point and numerical data corresponding to the decimal point position on the inferred display position on the display unit.