JPH09257509A - Data processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the excellent reaction without hindering the stability for data processing even in the case where a sudden change is generated in the data in a data processing device for processing the analog input data and for outputting a digital value. SOLUTION: In the case where a change of the input data of an input line 1 exists within a constant range, this input data is converted from analog to digital by an A/D converter 4, and plural data, which are converted to the digital value by the A/D converter, are moved for average by a means 6 for obtaining the moving average, and the moving average value is output to an output line 7. In the case where a change of the input data of the input line 1 exceeds the described range, this input data is converted by the A/D converter 4, and the data, which is converted to a digital value by the A/D converter, is output to the output line 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device in a device such as a scale for AD converting data.

[0002]

2. Description of the Related Art In general, in order to accurately measure a weight value, a factor of external noise included in data from a weight detection unit is removed. That is, this data is passed through a low-pass filter to remove the AC component to form only the DC component, the DC component is AD-converted into a plurality of time-series digital data, and a constant constant number of consecutive digital data is averaged. Then, the value obtained by removing the fluctuation by multiplying the moving average is used as the measurement value.

However, when the moving average is applied to the data in this way, for example, when the period required for the calculation of the moving average is T, and the operation is performed N times according to the number of data, (N-1) × A time delay of T occurs. Therefore, there is a drawback that the reaction of the measuring system becomes slow in the transitional period when the measuring system is not stable, such as when the weight changes abruptly by placing the object to be weighed on the balance.

For this reason, in the conventional scale, when it is detected that the weight change exceeds a certain range, the number of times of calculation of the moving average is reduced to make the reaction faster.

[0005]

However, in such a conventional method, the moving average is calculated several times even if the number is reduced, so that the tracking of data changes is delayed by that much. There is.

Further, there is a problem that the delay occurring in the low pass filter cannot be improved even though the time for moving average can be shortened.

Therefore, the present invention has as an object to solve such a problem and to make it possible to perform a favorable reaction even when a rapid change of data occurs without impairing the stability for data processing. And

[0008]

In order to achieve this object, the present invention is a data processor for processing analog input data and outputting it as a digital value, wherein the change of the input data is within a certain range. In the first case, the input data is AD-converted, a moving average of a plurality of data digitized by the AD conversion is output, and a change in the input data exceeds the range. In the case of, after the input data is AD converted,
It is characterized in that the data digitized by the AD conversion is directly output.

According to this structure, when the input data changes within a certain range and is in a stable state,
Since the moving average of the data after AD conversion is output, the stability of the data is ensured. In the case of a transient state in which the input data rapidly changes beyond the above range, the AD-converted data is output as it is without being subjected to a moving average, so that a quick reaction becomes possible.

The present invention also provides a first case used in the first case.
Input line and a second input line used in the second case, and a low-pass filter is provided on each of the first and second input lines to cut the low-pass filter on the first input line. The cutoff frequency of the low-pass filter of the second input line is set to be higher than the off frequency.

With such a configuration, when the input data is stable, a low-pass filter having a low cutoff frequency is used, so that accurate and stable data can be output. On the other hand, when the input data fluctuates, a low-pass filter with a high cutoff frequency is used, and a quick reaction is possible also from this point.

[0012]

FIG. 1 is a block diagram showing an example of a data processing device according to the present invention. This data processing device is used, for example, when processing the detection data of a balance or the like to obtain a measurement value.

In FIG. 1, reference numeral 1 is an input line capable of transmitting analog data. This input line 1 is branched via a changeover switch 2 into a first input line 1A and a second input line 1B, and these first and second input lines 1A and 1B have low-pass filters 3A and 3A, respectively. 3B is provided. Low pass filter 3A
Is set so that the cutoff frequency is, for example, a low nHz, and the lowpass filter 3B is set so that the cutoff frequency is higher than that of the lowpass filter 3A, for example, (n + m) Hz. Note that the specific values of these cutoff frequencies are appropriately determined according to the type of signal processed in the illustrated apparatus.

The output lines from the low-pass filters 3A and 3B are all connected to the AD converter 4. First
The output line 5A from the AD converter 4 corresponding to the input line 1A is connected to a means 6 for obtaining a moving average, which is constituted by a CPU or the like. On the other hand, the output line 5B from the AD converter 4 corresponding to the second input line 1B is connected to the output line 7 from the means 6 for obtaining the moving average.

A signal line 8 is branched from the input side of the means 6 for obtaining the moving average in the output line 5A, and this signal line 8 is led to the changeover switch 2. That is, the changeover switch 2 can be switched according to the status of the output from the AD converter 4 on the output line 5A.

In such a configuration, when the change in the analog input data on the input line 1 is stable within a certain range, the changeover switch 2 is switched to the first input line 1A, and the input data is changed. Is passed through the low-pass filter 3A having a low cut-off frequency of nHz, so that the AC component that causes noise is effectively removed. Then, the output signal from the low pass filter 3A is input to the AD converter 4 as the input signal A,
By undergoing AD conversion here, it becomes a plurality of discrete time-series digital data and is output to the output line 5A.

The means 6 for obtaining the moving average calculates the moving average by averaging consecutive constants in the time-series digital data, and outputs the result as a measured value to the output line 7. By applying the moving average in this way, fine fluctuations included in the time series data from the AD converter 4 are removed, and accurate and stable measurement values can be obtained.

Data from the AD converter 4 is sent to the signal line 8
Are picked up, and the changeover switch 2 is changed over according to the magnitude of the change. That is, since the magnitude of the change in the data on the signal line 8, that is, the output line 5A is related to the magnitude of the change in the analog input data on the input line 1, the transient state is determined based on the magnitude of the change in the data on the signal line 8. When it is determined that the change of the input data exceeds a certain range due to the occurrence of, the changeover switch 2 is changed over to the second input line 1B.

Then, the input data of the low-pass filter 3B having a higher cutoff frequency of (n + m) Hz is used.
Is input to Since the low-pass filter 3B has a higher responsiveness than the low-pass filter 3A of the first input line 1B because the cut-off frequency is higher, the low-pass filter 3B responds well to the transient state and the like.

Moreover, the input signal B output from the low pass filter 3B and then sent to the AD converter 4 is immediately sent to the output line 7 by the output line 5B without being multiplied by the moving average after being AD converted. Then, the sent data is used as a measurement value. For this reason, as compared with the case where the moving average is applied to the output line 5A as described above, the reactivity is significantly improved, and therefore a rapid change in the analog input data can be dealt with quickly.

If the change in the input data returns within a certain range due to the end of the transient state, the changeover switch 2
Is again switched to the first input line 1A, and stable data obtained by multiplying the moving average as before is obtained.

[0022]

As described above, according to the present invention, in the first case where the change of the input data is within a certain range, the input data is AD-converted and then digitized by this AD conversion. In addition to outputting a moving average of a plurality of data, in the second case where the change of the input data exceeds the above range, the input data is AD-converted and then the data digitized by this AD conversion. Since it is configured to output as it is, if the change of the input data is within a certain range and is in a stable state, the stability of the data can be secured, and if the input data exceeds the above range, A rapid reaction can be performed in the case of a rapidly changing transient state. Therefore, it is possible to ensure swiftness at the time of fluctuation without deteriorating the characteristics of the circuit and the processing for determining the accuracy of data processing at the stable time.

Further, according to the present invention, a low-pass filter is provided for each of the first input line used in the first case and the second input line used in the second case, and the low-pass filter of the first input line is provided. Since the cutoff frequency of the lowpass filter of the second input line is set higher than the cutoff frequency of the pass filter, the lowpass filter with a low cutoff frequency is used when the input data is stable. Therefore, accurate and stable data can be output, and if the input data fluctuates, a low-pass filter with a high cutoff frequency will be used. The swiftness of can be secured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a data processing device according to the present invention.

[Explanation of symbols]

 1 Input Line 2 Changeover Switch 3A Low Pass Filter 3B Low Pass Filter 4 AD Converter 6 Means for Obtaining Moving Average 7 Output Line

Claims (3)

[Claims] 1. A data processing device for processing analog input data and outputting it as a digital value, wherein when the change of the input data is within a certain range, the input data is AD. After the conversion, a value obtained by moving and averaging a plurality of data digitized by the AD conversion is output, and when the change of the input data exceeds the above range, the input data is AD-converted. Further, the data processing device is configured to output the data digitized by the AD conversion as it is. 2. Having a first input line for use in the first case and a second input line for use in the second case,
A low-pass filter is provided on each of the first and second input lines, and the cut-off frequency of the low-pass filter of the second input line is set higher than the cut-off frequency of the low-pass filter of the first input line. The data processing device according to claim 1, wherein 3. The method according to claim 1, wherein whether or not the change in the input data is within a certain range is determined based on the data after AD conversion and before moving average. The described data processing device.