JP4073049B2 - Waveform recorder waveform judgment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waveform determination method for a waveform recorder, and more specifically, sets a management value (management width) as a determination reference based on waveform data of the previous cycle, and determines waveform data captured in a memory in real time. The present invention relates to a waveform determination method for a waveform recorder.
[0002]
[Prior art]
In the waveform recorder, when it is checked whether or not the input waveform to be measured (determined waveform) is within a certain range, conventionally, as shown in FIG. An upper limit waveform 2a and a lower limit waveform 2b are generated by moving a sine wave matched to the frequency of the upper and lower directions by a set value (management width) D.
[0003]
In actual measurement, the zero cross of the waveform to be judged 1 and the zero cross of the management width D by the upper limit waveform 2a and the lower limit waveform 2b are combined, and it is determined in real time whether the waveform to be judged 1 does not exceed the management width D. Then, as illustrated in FIG. 7B, when a portion 1a of the waveform 1 to be judged deviates from the management width D, a trigger is applied at that time to display, for example, NG. .
[0004]
[Problems to be solved by the invention]
According to this, since the determination process can be performed in real time, the dead time hardly occurs, but there is a limitation that the management width D is limited to a sine wave. Further, since the management width D is fixed in advance, there is a disadvantage that the NG trigger is applied even when the amplitude of the waveform to be determined 1 changes gently, for example.
[0005]
The present invention has been made to solve such a problem, and its object is to set a management width based on the waveform to be determined itself and to perform waveform determination in real time. It is to provide a waveform determination method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention writes waveform data of an analog input signal digitally converted by an A / D converter into a memory via a storage controller, and converts the waveform data written in the memory into data to be judged. When the CPU (central processing unit) performs waveform determination by comparing with a predetermined management value, the CPU reads waveform data written at an address one cycle before the determined data from the memory. a comparison reference data Te, the waveform determination method of the waveform recorder for setting the control value based on the comparison reference data, includes a zero-cross detection circuit for detecting a zero-cross point of the analog input signal, the CPU is the zero-cross From the zero cross address at the time of receiving the zero cross signal from the detection circuit Together (the p positive integer) given p points prior to the waveform data of a predetermined address present in the above-be-determined data, for setting the control value one cycle before the waveform data of the to-be-determined data The above-mentioned comparison reference data, with the width p before and after the address of the comparison reference data as the center, and taking into account the maximum value and minimum value obtained by searching the address for the 2 × p width in one direction. The management value is set, and each time the comparison data is compared with the management value, the addresses of the determination data and the comparison reference data for the time corresponding to the time required for the comparison determination are It is characterized in that it is sequentially updated until a zero cross is detected.
[0007]
According to the present invention, since the management value (management width) corresponding to the waveform to be determined is set, it is not limited to a sine wave as in the prior art, and the degree of freedom is large, and the waveform is more accurate. The determination can be made in real time.
[0008]
In addition, the zero cross point of the analog input signal is detected by the zero cross detection circuit, and the waveform data at a predetermined address existing before the zero cross address at the time of receiving the zero cross signal is set as the determination target data, By using the comparison reference data for setting the management value as the waveform data one cycle before the determination target data, the comparison is made between the addresses out of the zero cross point.
[0009]
In addition, each time the comparison data is compared with the management value, the addresses of the determination data and the comparison reference data are sequentially updated by an amount corresponding to the time required for the comparison determination, so that the entire waveform to be determined It is possible to perform waveform determination over a wide range.
[0010]
Further, the comparison determination between the determination target data and the management value may be repeatedly performed in units of one cycle of the analog input signal with reference to the zero cross signal, and according to this, the waveform determination is performed for each cycle. .
[0011]
In setting the management width, the management width is set to the actual waveform to be determined by adding the maximum value and the minimum value obtained from the predetermined addresses including the address of the same data to the comparison reference data. It can be in line with.
[0012]
Further, in order to detect the maximum value and the minimum value from within a predetermined address, the operation steps of the CPU are reduced by looking at the address within a predetermined range from the address of the comparison reference data to the lower or higher direction. The processing burden can be further reduced.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, in order to better understand the technical idea of the present invention, embodiments thereof will be described with reference to the drawings.
[0014]
First, referring to FIG. 1, an analog input signal is amplified by an amplifier 11 and then converted to a digital signal by an A / D converter 12. The waveform data is stored in a DMA (direct memory access) as a storage controller. ) Is written to the memory 14 via 13. The DMA 13 stores waveform data in the memory 14 in accordance with the sampling clock of the A / D converter 12 regardless of the CPU 15, but the CPU 15 can read the address information as appropriate.
[0015]
This waveform recorder is provided with a zero cross detection circuit 16 for detecting a zero cross point of an analog input signal. When the CPU (central processing unit) 15 receives the zero-cross signal ZCS from the zero-cross detection circuit 16, it starts waveform determination processing based on the address information of the waveform data from the DMA 13.
[0016]
The CPU 15 is provided with the following four variables for performing this waveform determination process.
(1) ZCS-real: Address when the CPU 15 receives the ZCS
(2) ZCS-pre: the address when the previous ZCS was received
(As will be described later, the address is several points before the ZCS)
(3) real-jdg: address of data to be judged
(4) pre-jdg: address one cycle before real-jdg
Based on this assumption, the operation of the CPU 15 will be described based on the waveform diagrams of FIGS. 2 and 3 and the flowchart of FIG. First, when the zero-cross signal ZCS is output from the zero-cross detection circuit 16 (YES in step ST1), the CPU 15 reads the address at that time from the DMA 13 and writes the address in the variable ZCS-real (step ST2).
[0018]
Next, the CPU 15 copies the variable ZCS-pre of the previous ZCS address to the variable pre-jdg as the position one cycle before (step ST3). After the copying, the address (ZCSreal-p) several points p before the ZCS-real is written to the variable ZCS-pre, and the same address (ZCSreal-p) is also written to the variable real-jdg (step ST4).
[0019]
Thereafter, the CPU 15 sets a management width using the waveform data at the address designated as pre-jdg as comparison reference data (step ST5). In this embodiment, as shown in FIG. 3, for detecting the maximum value and the minimum value from among the predetermined number of waveform data existing before and after the address of the pre-JDG. Then, a predetermined value is added to the maximum value to obtain an upper limit value JLMAX of the management width, and a predetermined value is subtracted from the minimum value to obtain a lower limit value JLMIN of the management width.
[0020]
After setting the management width in this way, it is determined whether the waveform data at the address indicated by real-jdg is within the management width (JLMIN to JLMAX) (step ST6).
If YES, the process proceeds directly to the next stage (step ST7). If NO (outside the management range), for example, NG display is performed in step ST6a, and then the process proceeds to step ST7.
[0021]
In step ST7, the time required for the determination process is added to advance each address of pre-jdg and real-jdg, and step ST5 and step ST7 are repeated until the next zero cross signal ZCS is detected in step ST8. A management width is set using the waveform data of each pre-jdg as comparison reference data, and comparison with the waveform data of each real-jdg is performed.
[0022]
When the next zero cross signal is detected in step ST8, the process returns to step ST2, the above operation is repeated, and the management width based on the waveform data of the previous cycle is set.
In this way, according to the present invention, as illustrated in Figure 5, without the control range is limited to a sine wave as in the prior art, control width in line with the determination target waveform (see a chain line waveform) Can be set. Therefore, it does not respond to gentle amplitude fluctuations as shown in FIG. 5B, and it is possible to appropriately trigger only at the time of sudden amplitude fluctuations.
[0023]
The reason why the variable ZCS-pre is shifted by p points from the ZCS-real is to facilitate calculation when setting the management width so as to have a width in the time axis direction.
[0024]
In this case, as shown in FIG. 6 (a), the width p is provided at the front and back (both sides) around the address of pre-jdg, and the maximum value and the minimum value are detected therefrom. The CPU must look at data in the minus (lower) direction and the positive (upper) direction of pre-jdg.
[0025]
Therefore, as shown in FIG. 6B, by pre-decreasing the address of pre-jdg by p points in advance, the CPU only needs to search for an address corresponding to 2p width in the plus direction from that address. Thus, the burden on the CPU is reduced.
[0026]
【The invention's effect】
As described above, according to the present invention, when performing waveform determination by comparing a waveform to be determined with a predetermined management width (or management value), the waveform in which the management width is written at an address one cycle before. By setting the data as a reference, it is possible to set a management width according to the waveform to be judged without being limited to a sine wave as in the past, and in real time based on the management width. Waveform determination can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a waveform recorder for carrying out a waveform determination method of the present invention.
FIG. 2 is a waveform diagram showing variables used in the waveform determination method of the present invention on a waveform to be determined.
FIG. 3 is an explanatory diagram for explaining a waveform determination method of the present invention.
FIG. 4 is a flowchart for explaining a waveform determination processing operation according to the present invention.
FIG. 5 is a waveform diagram illustrating a management width set according to the present invention together with a waveform to be determined.
FIG. 6 is an explanatory diagram for explaining an address search method when setting a management width from pre-jdg waveform data in the present invention.
FIG. 7 is a waveform diagram showing a management width set at the time of conventional waveform determination together with a waveform to be determined.
[Explanation of symbols]
11 Amplifier 12 A / D Converter 13 DMA (Storage Controller)
14 Memory 15 CPU
16 Zero cross detection circuit

Claims (1)

The waveform data of the analog input signal converted to digital by the A / D converter is written in the memory via the storage controller, and the waveform data written in the memory is determined by the CPU (central processing unit) as the data to be determined. in control value and performing to the waveform judgment comparison, the CPU reads the waveform data from the memory is written in one cycle before the address of the to-be-determined data as the comparison reference data, in the comparison reference data In the waveform determination method of the waveform recorder for setting the management value based on
A zero-cross detection circuit for detecting a zero-cross point of the analog input signal is provided, and the CPU is a predetermined p points before (p is a positive integer) before the zero-cross address when the zero-cross signal is received from the zero-cross detection circuit. the waveform data of a predetermined address that exists with the above determination target data, one cycle before the waveform data of the to-be-determined data and the comparison reference data for setting the control value,
Set the management value by taking the maximum and minimum values obtained by searching the address for the 2 × p width in one direction with the width p before and after the address of the comparison reference data. , each of the comparison judgment between the to-be-determined data and the management value, the address component corresponding to the time required for the comparison judgment, each address of the to-be-determined data and the comparison reference data to the next zero-crossing is detected A waveform determination method for a waveform recorder, wherein the waveform recorder is sequentially updated.

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