JPH10142002A - Method for storing measured data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To thin out data efficiently and save storage capacity even when a change in changing rate of measured data is small. SOLUTION: After first data d0 and second data d1 are fetched, the data d0 and d1 are connected by a straight line at the sample time when third data d2 are fetched, and when a difference value Δd0 between a value d12 and actually measured value d1 on the straight line at the second sampling timing t1 is smaller than a specified reference value k, the data d0 and d1 are connected by a straight line again at a timing t3 when fourth data d3 are fetched. Then, when a difference value Δd01 between a value d13 and the actually measured value d1 on the new straight line at the second sampling timing t3 or a third difference value d02 is larger than the specified reference value k, and data d1 are abandoned (thinned out) and it is not stored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measurement data storage method for a measurement data storage device for storing various input signals supplied from the outside in a storage medium.

[0002]

2. Description of the Related Art Generally, a measurement data storage device fetches measurement data at a predetermined sampling period (measurement period) and stores the measurement data fetched at a predetermined storage period in a storage medium such as a floppy disk or a memory card. It has become. Conventionally, the storage period is set to be longer than or equal to the measurement period. If the storage cycle is longer, the “maximum value of a plurality of data measured during the storage cycle,
Representative values are stored by various methods such as storing the minimum two points, storing only the maximum value, storing only the minimum value, storing only the average value, etc. All of these are stored in the storage cycle. It is a memory for each.

[0003]

The storage of representative values obtained by the above-mentioned various methods for each storage cycle is effective for a signal that changes finely, but is meaningful for a measurement signal that does not change very much. There is a problem that a large amount of measurement data without data is recorded and the capacity of the storage medium is wasted.

The present invention has been made in view of the above problem, and efficiently stores measurement data without wasting the capacity of a storage medium even if the measurement data has relatively small changes. It is an object of the present invention to provide a measurement data storage method that can be performed.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for storing measured data, comprising the steps of:
A measurement data storage method of a measurement data collection device for storing in a storage means, wherein first, second, and third measurement data are fetched, and the first and third measurement values are connected by a straight line, A first difference value between the second actual measurement data and the value on the straight line at the time of the second acquisition is calculated, and the first difference value is compared with a predetermined reference value to obtain a first difference value. Is larger, the first and second measurement data are stored as they are, and at the time of the next fourth measurement data acquisition, the second, third, and fourth measurement data are The same processing as above is performed using the second data as new first data, the third data as new second data, and the fourth data as new third data. When the first difference value is smaller than the reference value, in the next fourth data acquisition, the measurement values of the first and fourth measurement data are connected by a straight line, and the second measurement data is A second difference value from the value on the new straight line at the time of the second acquisition is calculated, and a third difference value is calculated in the same manner, and the second and third difference values are compared with the predetermined reference value. Compare the values and discard the second data if the second or third difference is greater,
The third measurement data one time before the current acquisition is stored, and the same processing as above is repeated each time measurement data is acquired thereafter as a new first measurement value.

According to the present invention, since it is meaningless to acquire a measured value during a period in which a measured value change is small or a measured value does not change, a straight line approximation is performed in an area which does not deviate from a predetermined value. Since the measurement points between the straight lines are ignored, only the start point and the end point of the straight line are stored, and the amount of data to be stored can be reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a block diagram showing a configuration of a measurement data collection device according to an embodiment of the present invention.
The measurement data collection device includes a detector 1 for detecting a physical quantity to be measured, an A / D converter 2 for converting a measurement signal measured by the detector 1 from an analog quantity to a digital quantity,
It comprises a CPU 3 for taking in measured data from the D converter 2 at a predetermined sampling cycle, a temporary memory 4 for temporarily storing the taken in measured data, and a data memory 5 for storing collected data. Conventionally, measurement data to be collected is stored in the data memory 5 at regular intervals.
In the embodiment of the present invention, data is discarded when the conditions described below are satisfied, that is, data is thinned out and stored. The temporary memory 4 temporarily stores the captured data before performing the thinning process. The storage areas D ₀ , D ₁ ,..., D ₃ used in the following are allocated to the temporary memory 4. It should be noted that there may be a plurality of detectors 1, and data may be taken into the CPU 3 from each detector in a time-sharing manner.

Next, a storage process in the measurement data collection device, that is, a data collection operation will be described with reference to flowcharts shown in FIGS. 3, 4 and 5. When the measurement operation of data collection is started, it is first determined whether or not a sample time has arrived (step ST [hereinafter referred to as ST]).
1). When the sample time arrives, the data di (= d ₀ ) at that time is fetched (ST2). Then i = 0 performs Kano determination (ST3) is because it is set initial value and i = 0, this determination is YES, the data d ₀ temporarily to a storage area D ₀ of the temporary memory 4 It is stored (ST4). i is incremented by one, and here i = 1 (ST
5) Return to ST1. Then, it waits for the next sample time to arrive. When the sample time arrives, the second data d ₁ is captured (ST2). In ST3, it is determined whether i = 0. In this case, since the determination is NO, the next S
Proceed to T6. In ST6, it is determined whether i = 1 or not. At this stage, since i = 1, the data d ₁ at that time is stored in the storage area D.
₁ (ST7), and returns to step ST1 again.
Wait for the next sample time.

When the next sample time arrives,
(ST2), and determines whether i = 0
(ST3) is i = 0 of ST3, i = 1 of ST6,
Are NO, the process proceeds to ST8, and it is determined whether i = 2.
However, since this determination is YES, the data d at that time
_TwoTo storage area D_Two(ST9). The first of the above
T is the time when the eye data is imported₀, The second time t₁, 3rd
T is the time when the eye data is imported_ThreeThen the data d₀, D
₁, D_TwoAre as shown in FIG. This state
And storage area D₀, D_TwoD is the stored value of₀And d_TwoThe straight line
(ST10), and then the second data, i =
Value d on a straight line of 1₁₂And the second data d ₁And the difference value Δd
₀(ST12). Next, the obtained difference value Δd₀
Is larger than a predetermined reference value k (ST1).
3). When the determination is YES, that is, when the difference value is larger than the predetermined value
Contains the data d₀, D₁Is stored in the data memory 5
(ST14). Further, the storage area D₁Record the contents of
Storage area D₀To storage area D_TwoRecord the contents of
Storage area D₁(ST15). The variable i is set to 2 (ST
16) Return to step ST1. In ST1, the next sump
Time, ie, t shown in FIG._ThreeThe timing shown in
When the data arrives, the data di at that time, that is, the data
Data d_TwoAnd i = 0 in ST3 or i in ST6
= 1, but all are NO, and ST8
To determine if i = 2. Since this determination is YES, ST9
To the data d at that time_TwoTo storage area D_TwoRemember
(ST9). And the storage area D at this time₀And storage area
D_TwoData again with a straight line (ST10)
Similarly to the above, the processing from ST11 to ST13 is performed, and the same processing is performed.
Will be repeated.

On the other hand, the first initial value d₀, The second day
D₁, The third data d_TwoST
13 at Δd₀Is smaller than the predetermined value k,
Initial value data d when determination is NO in ST13₀Only data
Is stored in memory 5 (ST17), and variable i is incremented by one.
(ST18), and returns to the first step ST1. ST
At 1, the next sample time (t_ThreeWait) and then
When the time has arrived, i = 0 in step ST3, or in ST6.
It is determined whether i = 1 or i = 2 in ST8.
Therefore, in both cases, the determination is NO and the process moves to ST19, and it is determined whether i = 3.
Set. Since this determination is YES, data d_ThreeMemory
Area D_Three(ST20), and this time the storage area D₀Written in
Initial value d to remember₀And the storage area D_ThreeThe fourth to memorize
Measurement d_ThreeAre connected by a straight line (ST21). Then i = 1
Value d on a straight line₁₃To storage area D₁₃(ST22),
Storage area D in ST23₁From storage value of storage area D₁₃The value of the
d ₁₃And the difference Δd₀₁Ask for. Also, if i = 2
The value d on the line_{twenty three}To storage area D _{twenty three}(ST24), and
Storage area D_TwoFrom storage value of storage area D_{twenty three}The value of d_{twenty three}Destroy
The difference value d₀₂(ST25). This data Δ
d₀₁, Δd₀₂Is greater than or equal to a predetermined value k.
(ST26) If not large, i is incremented by one
(ST30), the process returns to step ST1, but the predetermined value is exceeded.
If large, the data d₁Is discarded (ST27) and now
Storage area D in which the measured value one time before the current time is stored_TwoDay of
Storage area D₀To the storage area D₁
(ST28), set i to 2 (ST29), and
Return to ST1. The first time t₀From the 4th
Sample time t_ThreeOf the second stage
The difference between the data value and the data on the straight line exceeds the specified reference value
If there is none, keep the same condition
Data will be collected. Sample tie at that time
At the time of the mining, the determination of whether i = 3 in ST19 is also N.
It becomes O and moves to ST31. In ST31, the data d₁
Step ST19 while stepping i until thinning occurs.
The same processing as in the chair ST26 was repeated, and there was thinning.
In this case (ST32), the process returns to ST1.

In the above embodiment, the value of the constant k may be set within a range where no inconvenience occurs. For example, it is determined in consideration of the accuracy range of the device, the accuracy range allowed by the user, and the like. Further, in the above-described embodiment, the case of processing the data to be fetched every time has been described. However, the present invention is not limited to this, and when the maximum value and the minimum value for each storage period are stored, Each of the above-described storage methods can be applied, and in this case, a condition that one of the storage methods is out of accuracy may be added.

[0012]

According to the present invention, the first and third measurement data values are connected by a straight line, for example, the difference between the value on the straight line and the second actual measurement value is smaller than a predetermined reference value, The next fourth measurement value and the first measurement value are connected by a straight line, and the difference between the value on the straight line corresponding to the second sample and the second actual measurement value, or the third difference Is larger than a predetermined reference value, the second data is discarded (thinned out), so that it is very effective even when the change rate of the change rate of the measured data is small, and the storage capacity can be largely saved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a measurement data collection device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a lapse of a sample time and a change in a measured value in the measurement data collection device of the embodiment.

FIG. 3 is a flowchart illustrating a data storage process of the measurement data collection device of the embodiment.

FIG. 4 is a flowchart, together with FIG. 3, for explaining a data storage process of the measurement data collection device of the embodiment.

FIG. 5 is a flowchart, together with FIGS. 3 and 4, for explaining a data storage process of the measurement data collecting apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detector 2 A / D converter 3 CPU 4 Temporary memory 5 Data memory

Claims (1)

[Claims] 1. A measurement data storage method for a measurement data collection device, wherein measurement data is fetched at a predetermined cycle and stored in a storage means, wherein the first, second, and third measurement data are fetched. The first and third measurement values are connected by a straight line, and the first difference value between the second actual measurement data and the value on the straight line at the time of the second acquisition is calculated, and the first difference value is calculated. And a predetermined reference value, and when the first difference value is larger, the first and second measurement data are stored as they are, and the next fourth measurement value is stored.
At the time of the second measurement data acquisition, the second data is new first data, and the third data is new second data for the second, third, and fourth measurement data. , And the same processing as above is performed using the fourth data as new third data. If the first difference value is smaller than the reference value, in the next fourth data acquisition,
The measured values of the first and fourth measurement data are connected by a straight line, and a second difference value between the second actual measurement data and a value on a new straight line at the time of the second acquisition is calculated. The third difference value is calculated in the same manner, and the second and third difference values are compared with the predetermined reference value. If the second or third difference value is larger, the second difference value is calculated. The data is discarded, the third measurement data one time before the current acquisition is stored, and a new first measurement data is stored.
A measurement data storage method in which the same processing as described above is repeated every time measurement data is taken in as a second measurement value.