JP2012154761A - Measurement device and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve determination accuracy when determining quality of a determination target in an AC signal even when the cycle of the AC signal fluctuates.SOLUTION: The measurement device includes a processing unit which executes determination processing for defining an AC signal S1 of one cycle as a determination target, defining the AC signal S1 of one cycle input before the determination target as a comparison target Uc, and determining quality of the determination target based on the comparison result of an upper limit B and a lower limit C set for instantaneous values Ac (Ac1 to Ac17) of the comparison target Uc acquired by sampling processing with an instantaneous value of the determination target. The processing unit calculates, when the numbers of acquired instantaneous values of the comparison target Uc acquired by the sampling processing and the determination target are different from each other, the number of instantaneous values equal to the number of acquired instantaneous values Ac of the comparison target Uc by an interpolation formula specified based on the instantaneous values of the determination target acquired by the sampling processing by the interpolation formula, and executes the determination processing by using the calculated instantaneous value and the instantaneous value Ac of the comparison target Uc.

Description

  The present invention relates to a measuring apparatus and a determination method for determining pass / fail of a determination target for one or more periods in an input AC signal.

  As this type of apparatus, a waveform recorder disclosed by the applicant in Japanese Patent Application Laid-Open No. 10-19597 is known. This waveform recorder includes an amplifier, an A / D converter, a DMA, a memory, a CPU, a zero cross detection circuit, and the like. In this waveform recorder, the A / D converter converts the input signal amplified by the amplifier into waveform data, and the DMA writes the waveform data in the memory. Further, the CPU reads address information when the waveform data is written in the memory by DMA. The zero-cross detection circuit detects the zero-cross point of the input signal and outputs a zero-cross signal, and the CPU performs a waveform determination process based on the address information when the zero-cross signal is input. In this waveform determination process, the CPU sets a management width for the waveform data at the address one cycle before the address of the determination target data. Specifically, a maximum value and a minimum value are detected from a plurality of waveform data existing before and after the address one cycle before, and a predetermined value is added to the maximum value to obtain an upper limit value of the management width. The predetermined value is subtracted to obtain the lower limit value of the management width. Next, it is determined whether or not the determination target data is within the set management width. That is, in this waveform recorder, a band-like range obtained by adding / subtracting a predetermined value to / from the waveform one cycle before the waveform to be determined is set as a determination range, and whether or not the waveform to be determined is included in the determination range. Whether the input signal is good or bad is determined.

Japanese Patent Laid-Open No. 10-19597 (page 3-4, FIG. 1-5)

  However, the conventional waveform recorder described above has the following problems to be improved. That is, in the above waveform recorder, the management width is set for the waveform data at the address one cycle before the address of the data to be determined, and the input signal depends on whether or not the data to be determined is within the set management width. Is determined. On the other hand, in this type of apparatus, A / D conversion is generally performed at a predetermined period. For this reason, for example, when the frequency of the input signal fluctuates and the wavelength for one period to be determined is longer than the wavelength for one period to be compared one period before, it is generated by A / D conversion. This means that the number of determination target data to be determined is larger than the number of comparison target data. For this reason, when the frequency of the input signal fluctuates in this way, there may be no data to be compared corresponding to a part of the data to be judged, which results in the accuracy of the quality judgment of the input signal. There is a risk of lowering, and improvement of this point is desired.

  The present invention has been made in view of the problems to be improved, and improves the determination accuracy when determining the quality of the determination target in the AC signal even when the cycle (frequency) of the AC signal varies. The main object is to provide a measuring device and a determination method.

  In order to achieve the above object, the measuring apparatus according to claim 1 includes a sampling unit that executes a sampling process for acquiring an instantaneous value of an input AC signal at a predetermined sampling period, and the AC for one or more periods. The signal is defined as a determination target, and the AC signal for the same number of cycles as the determination target input earlier in time than the determination target is defined as a comparison target, and corresponds to the instantaneous value of the determination target Comparing the upper limit value obtained by adding a predetermined addition value to the instantaneous value to be compared and the lower limit value obtained by subtracting the predetermined subtraction value from the instantaneous value and the instantaneous value of the determination target And a processing unit that executes a determination process for determining pass / fail for the determination target based on the result, wherein the processing unit performs the sampling process. The sampling process in one of the comparison object and the determination object when the obtained acquisition value of the instantaneous value of the comparison object is different from the acquisition value of the instantaneous value of the determination object acquired by the sampling process Interpolating processing for specifying the interpolation formula for the one of the ones based on the instantaneous value acquired by the calculation method and calculating the same number of instantaneous values from the interpolation formula as the other acquisition number of the comparison target and the determination target. And performing the determination process using the instantaneous value calculated by the interpolation process and the instantaneous value acquired by the sampling process on the other side.

  According to a second aspect of the present invention, there is provided a measuring device that performs a sampling process for acquiring an instantaneous value of an input AC signal at a predetermined sampling period, and determines the AC signal for one or more periods as a determination target. And defining the AC signal for the same number of cycles as the determination target input earlier in time than the determination target as the comparison target, and the comparison target corresponding to the instantaneous value of the determination target Based on the comparison result by comparing the upper limit value obtained by adding a predetermined addition value to the instantaneous value and the lower limit value obtained by subtracting the predetermined subtraction value from the instantaneous value and the instantaneous value of the determination target And a processing unit that executes a determination process for determining pass / fail for the determination target, wherein the processing unit is acquired by the sampling process. The interpolation formulas for the comparison target and the determination target are specified based on the time value, and the instantaneous value of the comparison target and the instantaneous value of the determination target are respectively calculated from the interpolation formula by the same number. Interpolation processing is performed, and the determination processing is executed using the instantaneous value calculated by the interpolation processing.

  The measuring device according to claim 3 is the measuring device according to claim 1 or 2, wherein the sampling unit acquires the instantaneous value as an integer value in the sampling process, and the processing unit performs the sampling process. The acquired instantaneous value is converted from an integer value to a floating-point format, the interpolation formula is specified, the instantaneous value in the floating-point format is calculated from the interpolation formula, and the calculated instantaneous value is converted into an integer value from the floating-point format. And the upper limit value and the lower limit value are compared with the instantaneous value of the converted integer value.

  According to a fourth aspect of the present invention, in the measurement apparatus according to any one of the first to third aspects, a second-order or higher-order interpolation equation is specified as the interpolation equation.

  According to a fifth aspect of the present invention, the determination method according to claim 5 executes a sampling process for acquiring an instantaneous value of the input AC signal at a predetermined sampling period, and defines the AC signal for one or more periods as a determination target. In addition, the AC signal for the same number of cycles as the determination target input earlier than the determination target is defined as a comparison target, and the instantaneous value of the comparison target corresponding to the instantaneous value of the determination target An upper limit value obtained by adding a predetermined addition value and a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value are compared with the instantaneous value of the determination target, and the determination target is determined based on the comparison result. A determination method for determining whether or not the image is good or bad, comprising: obtaining the number of the instantaneous values to be compared obtained by the sampling process and the sampling process. When the number of acquisitions of the instantaneous value of the determination target acquired by is different from that of the comparison target and the determination target based on the instantaneous value acquired by the sampling processing in one of the comparison target and the determination target Specifying and performing an interpolation process to calculate the same number of instantaneous values as the other acquisition number of the comparison target and the determination target from the interpolation formula, and calculating the instantaneous value calculated by the interpolation process and the sampling process in the other The determination process is executed using the instantaneous value acquired by the above.

  The determination method according to claim 6 executes sampling processing for acquiring an instantaneous value of the input AC signal at a predetermined sampling period, and defines the AC signal for one or more periods as a determination target. In addition, the AC signal for the same number of cycles as the determination target input earlier than the determination target is defined as a comparison target, and the instantaneous value of the comparison target corresponding to the instantaneous value of the determination target An upper limit value obtained by adding a predetermined addition value and a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value are compared with the instantaneous value of the determination target, and the determination target is determined based on the comparison result. It is a determination method for executing a determination process for determining pass / fail for the comparison object and the determination object based on the instantaneous value acquired by the sampling process. Each of the interpolation formulas is determined, and the instantaneous value calculated by the interpolation processing is performed by calculating the instantaneous value of the comparison target and the instantaneous value of the determination target from the respective interpolation formulas by the same number. The determination process is executed using a value.

  In the measuring apparatus according to claim 1 and the determination method according to claim 5, when the number of acquired instantaneous values of the comparison target acquired by the sampling process is different from the number of acquired instantaneous values of the determination target, the comparison target and the determination Based on the instantaneous value of one of the targets, the interpolation formula for one of them is specified, and the interpolation processing is performed to calculate the same number of instantaneous values as the other acquisition target and comparison target from the interpolation formula. The determination process is executed using the instantaneous value obtained and the instantaneous value acquired by the sampling process on the other side. Therefore, according to this measuring apparatus and determination method, the same number of instantaneous values can be acquired or calculated for the comparison target and the determination target by performing this interpolation process. Therefore, according to this measuring apparatus and determination method, even if the frequency of the AC signal fluctuates, it corresponds to all the instantaneous values in the determination target calculated by the interpolation process and each of these instantaneous values. As a result of reliably comparing the upper limit value and the lower limit value set for each instantaneous value to be compared, it is possible to sufficiently increase the determination accuracy when determining pass / fail of the determination target based on the comparison result. .

  The measuring apparatus according to claim 2 and the determination method according to claim 6 specify each interpolation formula for the comparison object and the determination object based on the instantaneous value acquired by the sampling process, and determine the instantaneous value and determination of the comparison object. Interpolation processing is performed to calculate the same instantaneous number of the target from each interpolation formula, and the determination processing is executed using the instantaneous value calculated by the interpolation processing. Therefore, according to this measuring apparatus and determination method, all the instantaneous values in the determination target calculated by the interpolation process, and the upper limit value and the lower limit set for each instantaneous value of the comparison target corresponding to each of these instantaneous values, respectively. As a result of reliably comparing the values, even when the frequency of the AC signal is fluctuating, it is possible to sufficiently increase the determination accuracy when determining the quality of the determination target based on the comparison result. it can. In addition, according to this measuring apparatus and determination method, the number of instantaneous values to be calculated can be defined as an arbitrary number, so that the number is defined as the number of powers of 2 effective for efficient FFT calculation. Thus, for example, it is possible to sufficiently improve the calculation efficiency when the physical quantity for the determination target is obtained by the FFT calculation using the calculated instantaneous value.

  According to the third aspect of the present invention, the instantaneous value acquired as an integer value in the sampling process is converted into a floating-point format to specify the interpolation formula, and the instantaneous value in the floating-point format is calculated from the interpolation formula. As a result, the interpolation formula can be specified accurately, and the instantaneous value can be accurately calculated from the interpolation formula. Further, according to this measuring apparatus, the calculated instantaneous value is converted from the floating-point format to an integer value, and the upper limit value and the lower limit value are compared with the converted instantaneous value, whereby the upper limit value, the lower limit value, and the instantaneous value are Can be performed at high speed. When converting from a floating-point format to an integer value, the data capacity is reduced, such as a 16-bit integer value for a 32-bit floating-point format, in order to increase the effectiveness of high-speed processing. It is desirable to make it an integer.

  In the measuring apparatus according to the fourth aspect, a second-order or higher-order interpolation equation is specified as the interpolation equation. In this case, the higher-order interpolation equation of the second order or higher generally performs accurate interpolation even when the AC signal changes abruptly as compared with the primary interpolation equation (linear interpolation equation). Can do. For this reason, according to this measuring apparatus, even when the AC signal changes rapidly in time, the instantaneous value can be accurately calculated, and as a result, the instantaneous value is compared with the upper limit value and the lower limit value. It is possible to accurately determine the quality of the determination target based on the comparison result.

1 is a configuration diagram showing a configuration of a measuring device 1. FIG. It is a signal waveform diagram which shows an example of alternating current signal S1 which the measuring apparatus 1 inputs. FIG. 3 is a first explanatory view explaining the operation of the measuring apparatus 1. FIG. 6 is a second explanatory diagram for explaining the operation of the measuring apparatus 1. FIG. 6 is a third explanatory diagram for explaining the operation of the measuring apparatus 1. FIG. 6 is a fourth explanatory view for explaining the operation of the measuring apparatus 1.

  Hereinafter, embodiments of a measuring apparatus and a determination method will be described with reference to the accompanying drawings.

  Initially, the structure of the measuring apparatus 1 as an example of a measuring apparatus is demonstrated. A measuring apparatus 1 shown in FIG. 1 includes a signal processing unit 11, a sampling unit 12, an operation unit 13, a display unit 14, a storage unit 15, a storage control unit 16, and a processing unit 17, and an input AC signal S1 (as an example, As shown in FIG. 2, the physical quantity (for example, the effective value of voltage) about a sine wave AC voltage signal) is configured to be measurable. The measuring apparatus 1 is configured to be able to determine whether the input AC signal S1 is good or bad.

  The signal processing unit 11 performs signal processing for removing noise components included in the input AC signal S1. The signal processing unit 11 is associated with the frequency of the AC signal S1 (nominal frequencies: 50 Hz and 60 Hz) and has a plurality of (for example, two) filter circuits (not shown) having different electrical characteristics. It is configured with. In this case, the filter circuit is composed of a band-pass filter that removes a component having a frequency higher than that of the nominal frequency included in the AC signal S1 and a component having a frequency lower than that of the nominal frequency (that is, extracting a component having the nominal frequency). Further, the signal processing unit 11 performs predetermined signal processing on the AC signal S <b> 1 by a filter circuit switched from among the plurality of filter circuits by a switching operation on the operation unit 13.

  The sampling unit 12 includes a sampling clock generation circuit and a sampling circuit (both not shown). The sampling clock generation circuit generates a sampling clock having a predetermined sampling period Ts (see FIG. 3). The sampling circuit samples the AC signal S1 in synchronization with the sampling clock to acquire an instantaneous value A of the AC signal S1, and executes a sampling process for outputting digital data (sampling data) Dd indicating the instantaneous value A. In this case, the digital data Dd is used for determination of the quality of the AC signal S1 in a determination process described later executed by the processing unit 17, and a physical quantity of the AC signal S1 in a measurement process described later executed by the processing unit 17 ( For example, it is used to measure the effective value of voltage.

  The operation unit 13 includes various switches for performing an operation for instructing a measurement start, a switching operation for switching a nominal frequency (switching a filter circuit), and the like. Output. The display unit 14 displays various images and measurement values under the control of the processing unit 17. The storage unit 15 is configured to be able to store the digital data Dd output from the sampling unit 12 under the control of the storage control unit 16.

  The storage control unit 16 is for one cycle Ta (see FIG. 2) of the AC signal S1 divided by zero cross (for example, rising zero cross), or for a plurality of cycles in which one cycle Ta is continuous (in this example, Each time digital data Dd for one cycle Ta) is output, a storage process for storing the digital data Dd in the storage unit 15 for each cycle Ta is executed. Further, the storage control unit 16 is configured by an FPGA (Field Programmable Gate Array) as an example. Note that the storage control unit 16 may be configured with a CPU together with the processing unit 17.

  The processing unit 17 controls each unit constituting the measuring apparatus 1 according to the operation signal So output from the operation unit 13. Further, the processing unit 17 executes a determination process for determining whether the AC signal S1 is good or bad using the digital data Dd. In this determination process, the processing unit 17 defines the AC signal S1 for one cycle Ta or a plurality of cycles (in this example, one cycle Ta) as the determination target Uj, and the AC signal for each determination target Uj. The quality of S1 is determined.

  In this case, the processing unit 17 inputs the AC signal S1 for the same number of cycles as the determination target Uj (in this example, one cycle Ta), which is input earlier (as an example, immediately before) than the determination target Uj. Is defined as the comparison target Uc (hereinafter, the comparison target Uc and the determination target Uj are also collectively referred to as “target Uc, Uj”), and each instantaneous value A (hereinafter referred to as a comparison) indicated by each digital data Dd in the comparison target Uc. Based on the instantaneous value A of the target Uc is also referred to as “instantaneous value Ac”), an upper limit value B and a lower limit value C for pass / fail judgment are set (calculated). Further, the processing unit 17 is set based on the instantaneous value Ac of the comparison target Uc corresponding to each instantaneous value A of the determination target Uj (hereinafter, the instantaneous value A of the determination target Uj is also referred to as “instantaneous value Aj”). The upper limit B and the lower limit C are compared, and pass / fail is determined based on the comparison result.

  Further, the processing unit 17 acquires the number Nc of acquisitions of the instantaneous value Ac of the comparison target Uc and the number of acquisitions Nj of the instantaneous value Aj of the determination target Uj acquired by the sampling process executed by the sampling unit 12 (hereinafter, the acquisition numbers Nc, Nj). Is different from “acquisition number N”), an interpolation equation for one of the targets Uc and Uj acquired by the sampling process is specified based on the instantaneous value A, and Interpolation processing is performed on the other of the objects Uc and Uj to obtain the same number of instantaneous values A as the number N obtained from the interpolation formula, and the other instantaneous value A acquired by the sampling processing and one of the instantaneous values calculated by the interpolation processing are calculated. The determination process is executed using the value A.

  In addition, the processing unit 17 performs a measurement process and measures the physical quantity (for example, the effective value of the voltage) of the AC signal S1 using the digital data Dd stored in the storage unit 15. Further, the processing unit 17 causes the display unit 14 to display the result of the determination process described above and the measured physical quantity.

  Next, a determination method for determining pass / fail of the AC signal S1 using the measurement apparatus 1 and the operation of the measurement apparatus 1 at that time will be described.

  In this measuring apparatus 1, when an operation for instructing the operation unit 13 to start measurement is performed, a filter circuit of the signal processing unit 11 (for example, a filter circuit for 50 Hz) is input via a signal cable. The signal processing for removing the noise component of the AC signal S1 is started, and the processed AC signal S1 is output to the sampling unit 12. Further, the sampling clock generation circuit of the sampling unit 12 generates a sampling clock having a predetermined sampling period Ts (see FIG. 3). The sampling circuit of the sampling unit 12 executes sampling processing, samples the AC signal S1 in synchronization with the sampling clock, acquires the instantaneous value A of the AC signal S1, and digital data indicating the instantaneous value A Dd is output. In this case, the sampling unit 12 acquires the instantaneous value A as an integer value, and outputs digital data Dd indicating the integer instantaneous value A.

  Next, as shown in FIG. 2, the storage control unit 16 detects the crossing (zero crossing) between the AC signal S1 and the reference value (0V), and determines one cycle Ta of the AC signal S1 divided by the rising zero crossing. It is specified based on the digital data Dd. In addition, the storage control unit 16 executes the storage process and causes the storage unit 15 to store the digital data Dd for each cycle Ta every time the digital data Dd for one cycle Ta is output.

  Subsequently, the processing unit 17 executes a determination process. In this determination processing, when the digital data Dd for the first one cycle Ta is output, the processing unit 17 defines the AC signal S1 for one cycle Ta as the comparison target Uc (see FIG. 3). ), An upper limit value B and a lower limit value C for pass / fail judgment are set using the digital data Dd (see the figure). Specifically, the processing unit 17 adds a predetermined addition value to each instantaneous value Ac (for example, the instantaneous values Ac1 to Ac17 shown in the figure) indicated by each digital data Dd in the comparison target Uc. By doing so, the upper limit value B is set. The processing unit 17 sets the lower limit C by subtracting a predetermined subtraction value from each instantaneous value A.

  Next, the processing unit 17 stores the upper limit value B and the lower limit value C set as described above in the storage unit 15. Subsequently, when the digital data Dd for the next one cycle Ta is output, the processing unit 17 defines the AC signal S1 for the one cycle Ta as the determination target Uj (see FIG. 4). Next, the processing unit 17 compares the acquisition number Nc of the instantaneous value Ac of the comparison target Uc acquired by the sampling process with the acquisition number Nj of the instantaneous value Aj of the determination target Uj, and the acquisition numbers Nc and Nj are the same. Determine if it exists or is different.

  In this case, when the frequency of the AC signal S1 is not fluctuating, as shown in FIGS. 3 and 4, the acquisition number Nc (same as the instantaneous values Ac (for example, the instantaneous values Ac1 to Ac17 shown in FIG. 3)) in the comparison target Uc. In the example of the figure, 17) and the acquisition number Nj (17 in the example of the figure) of the instantaneous value Aj (for example, the instantaneous values Aj1 to Aj17 shown in FIG. 4) in the determination target Uj are the same number. At this time, the processing unit 17 determines that the acquisition numbers Nc and Nj are the same, and subsequently, sets the upper limit value B set for the instantaneous value Ac (of the same phase) corresponding to the instantaneous value Aj of the determination target Uj and The lower limit C is read from the storage unit 15 and compared with the instantaneous value Aj, and pass / fail is determined based on the comparison result. Specifically, when all of the instantaneous values Aj of the determination target Uj are included between the lower limit C and the upper limit B, the processing unit 17 determines that the determination target Uj is good, and determines the determination target Uj When there is even one instantaneous value Aj that is not included between the lower limit C and the upper limit B, the determination target Uj is determined to be defective.

  On the other hand, when the frequency of the AC signal S1 is fluctuating, as shown in FIGS. 3 and 5, the number Nc (17 in this example) of acquisition of the instantaneous value Ac in the comparison target Uc and the instantaneous value Aj in the determination target Uj. (For example, the instantaneous values Aj1 to Aj19 shown in FIG. 5) may be different from the number of acquisitions Nj (19 in the example of FIG. 5). At this time, the processing unit 17 determines that the acquisition numbers Nc and Nj are different, and then determines the determination target Uj based on the instantaneous value Aj of one of the targets Uc and Uj acquired by the sampling process (for example, the determination target Uj). Specify the interpolation formula for. In this case, the processing unit 17 converts the instantaneous value Aj acquired by the sampling process executed by the sampling unit 12 from an integer value to a floating point format, and specifies an interpolation formula. By performing such conversion when specifying the interpolation formula, the interpolation formula can be specified accurately.

  Subsequently, the processing unit 17 performs an interpolation process on the determination target Uj. In this interpolation processing, as shown in FIG. 6, the processing unit 17 has the same number (17 in this example) of instantaneous values Aj as the number of acquisitions Nc in the other of the objects Uc and Uj (in this example, the comparison target Uc). (For example, instantaneous values Aj1 to Aj17 shown in the figure) are calculated from the specified interpolation formula. In this case, the processing unit 17 makes the time intervals of the instantaneous values Aj equal (so as to be equally spaced along the x-axis in the figure: one period in the figure is compared with the comparison target Uc in FIG. 3). (Time interval divided by the number of acquisitions Nc) Each instantaneous value Aj is calculated. Further, the processing unit 17 calculates the instantaneous value Aj in a floating point format. As described above, by performing the calculation in the floating point format, it is possible to sufficiently improve the accuracy of equality of the time intervals of the respective instantaneous values Aj.

  Next, the processing unit 17 converts the calculated instantaneous value Aj from the floating-point format to an integer value, and subsequently the instantaneous value Ac corresponding to the instantaneous value Aj (the temporal order in the comparison target Uc is equal). The set upper limit value B and lower limit value C are read from the storage unit 15 and compared with the instantaneous value Aj, and pass / fail is determined based on the comparison result. That is, the determination process is executed using the instantaneous value Aj (instantaneous values Aj1 to Aj17) calculated by the interpolation process and the instantaneous value Ac acquired by the sampling process. In this case, as described above, by converting the calculated instantaneous value Aj from the floating-point format to an integer value, the process of comparing the upper limit value B and the lower limit value C with the instantaneous value Aj can be performed at high speed. As the above-described interpolation formula, a primary interpolation formula (linear interpolation formula) and a higher-order interpolation formula of the second or higher order can be used. In this example, a Lagrange interpolation formula as an example of the high-order interpolation formula is used. Is used.

  In the measuring apparatus 1, as described above, when the acquisition numbers Nc and Nj in the targets Uc and Uj are different, interpolation processing is performed on one of the targets Uc and Uj, and the acquisition number N in the other of the targets Uc and Uj The same number of instantaneous values A are calculated from the interpolation formula. That is, in the measuring apparatus 1, the same number of instantaneous values A are acquired or calculated for the objects Uc and Uj by performing an interpolation process. For this reason, even if the frequency of the AC signal S1 is fluctuating, all the instantaneous values Aj in the determination target Uj calculated by the interpolation process and the respective instantaneous values Ac corresponding to the respective instantaneous values Aj, respectively. The set upper limit value B and lower limit value C can be reliably compared. Therefore, in this measuring apparatus 1, it is possible to sufficiently increase the determination accuracy when determining the quality of the determination target Uj in the AC signal S1 based on the comparison result between the instantaneous value Aj and the upper limit value B and the lower limit value C. It has become.

  In the above example, the same number of instantaneous values Aj as the number Nc of acquired instantaneous values Ac of the comparison target Uc are calculated from the interpolation formula for the determination target Uj specified based on the instantaneous value Aj of the determination target Uj. However, on the contrary, the same number of instantaneous values Ac as the instantaneous values Aj of the determination target Uj can be calculated from the interpolation formula for the comparison target Uc specified based on the instantaneous value Ac of the comparison target Uc. In this case, the specification of the interpolation formula and the calculation of the instantaneous value Ac from the interpolation formula can be performed in the same manner as described above.

  Thereafter, the processing unit 17 executes the above-described determination process every time digital data Dd for one cycle Ta is output. In addition, the processing unit 17 performs measurement processing in parallel with the determination processing, and measures the physical quantity (for example, the effective value of the voltage) of the AC signal S1 using the digital data Dd stored in the storage unit 15. In addition, the processing unit 17 causes the display unit 14 to display the determination processing result and the measured physical quantity.

  As described above, in the measurement apparatus 1 and the determination method, when the acquisition numbers N of the instantaneous values A of the targets Uc and Uj acquired by the sampling process are different from each other, based on one instantaneous value A of the targets Uc and Uj. While specifying the interpolation formula, an interpolation process is performed to calculate the same instantaneous value A as the other acquisition number N of the targets Uc and Uj from the specified interpolation formula, and the other instantaneous value of the targets Uc and Uj acquired by the sampling process The determination process is executed using the value A and the instantaneous value A calculated by the interpolation process. Therefore, according to the measurement apparatus 1 and the determination method, the same number of instantaneous values A can be acquired or calculated for the objects Uc and Uj by performing this interpolation process. Therefore, according to the measuring apparatus 1 and the determination method, even if the frequency of the AC signal S1 is fluctuating, all the instantaneous values Aj in the determination target Uj calculated by the interpolation process, and each of these instantaneous values As a result of reliably comparing the upper limit value B and the lower limit value C set for each instantaneous value Ac respectively corresponding to Aj, the determination accuracy when determining the quality of the determination target Uj based on the comparison result It can be raised enough.

  Further, according to the measuring apparatus 1 and the determination method, the instantaneous value A acquired as an integer value in the sampling process is converted into the floating point format to specify the interpolation formula, and the instantaneous value A in the floating point format is determined from the interpolation formula. By calculating, the interpolation formula can be specified accurately and the instantaneous value A can be calculated accurately from the interpolation formula. Further, according to the measuring apparatus 1 and the determination method, the calculated instantaneous value A is converted from the floating-point format to an integer value, and the upper limit value B and the lower limit value C are compared with the converted instantaneous value A to obtain the upper limit value. The process of comparing the value B and the lower limit C with the instantaneous value A can be performed at high speed. When converting from a floating-point format to an integer value, the data capacity is reduced, such as a 16-bit integer value for a 32-bit floating-point format, in order to increase the effectiveness of high-speed processing. It is desirable to make it an integer.

  Further, in the measurement apparatus 1 and the determination method, a secondary or higher order interpolation equation is specified as the interpolation equation. In this case, the second-order or higher-order interpolation equation generally performs accurate interpolation even when the AC signal S1 changes rapidly in time, as compared with the primary interpolation equation (linear interpolation equation). be able to. For this reason, according to this measuring apparatus 1 and the determination method, even when the AC signal S1 changes rapidly in time, the instantaneous value Aj can be accurately calculated. As a result, the instantaneous value Aj, the upper limit value B, and The comparison with the lower limit C and the quality of the determination target Uj based on the comparison result can be accurately determined.

  Note that the measurement device and the determination method are not limited to the above configuration and method. For example, when the acquisition number Nc of the instantaneous value Ac of the comparison target Uc acquired by the sampling process is different from the acquisition number Nj of the instantaneous value Aj of the determination target Uj, an interpolation process is performed on one of the targets Uc and Uj. Although the configuration and method have been described above, the interpolation formula for the comparison target Uc and the interpolation formula for the determination target Uj are respectively specified regardless of whether the acquisition number Nc and the acquisition number Nj are different, and the targets Uc and Uj The instantaneous value Ac of the comparison target Uc and the instantaneous value Aj of the determination target Uj are calculated from the respective interpolation equations by the same calculation number M, respectively, and the determination is performed using the calculated instantaneous value A. A configuration and a method for executing the processing can also be adopted. In this case, the specification of the interpolation formula and the calculation of the instantaneous values Ac and Aj from the interpolation formula can be executed in the same manner as described above. Also in this configuration and method, all the instantaneous values Aj in the determination target Uj calculated by the interpolation process, and the upper limit value B and the lower limit value C set for each instantaneous value Ac corresponding to each of the instantaneous values Aj are obtained. As a result of the reliable comparison, even when the frequency of the AC signal S1 varies, the determination accuracy when determining the quality of the determination target Uj based on the comparison result can be sufficiently increased. . Further, according to this configuration and method, since the calculated number M can be defined as an arbitrary number, by defining the calculated number M as a power of 2 effective for efficient FFT calculation, for example, It is possible to sufficiently improve the calculation efficiency when a physical quantity for the determination target Uj is obtained by FFT calculation using the calculated instantaneous value Aj. In this case, the calculated number M can be defined as the same numerical value as one of the acquisition number Nc and the acquisition number Nj. Moreover, it can be prescribed | regulated to a numerical value larger than any one of the acquisition number Nc and the acquisition number Nj, and can be prescribed | regulated to a numerical value smaller than any one of the acquisition number Nc and the acquisition number Nj. Furthermore, when the acquisition number Nc and the acquisition number Nj are numerical values different from each other, it can be defined as an arbitrary numerical value between the two numerical values.

  Further, the configuration and method for defining the AC signal S1 for one cycle Ta as the determination target Uj and the comparison target Uc have been described above. However, the AC signal S1 for a plurality of cycles is defined as the determination target Uj, and the determination target Uj It is also possible to employ a configuration and method that define the AC signals S1 for the same number of cycles as the comparison target Uc.

In addition, the configuration and the method for defining the AC signal S1 input immediately before the determination target Uj as the comparison target Uc have been described above. However, the AC signal S1 input before the determination target Uj is input two cycles or more (temporally ahead) (the determination target Uj It is also possible to adopt a configuration and method for defining the AC signal S1 as an object to be compared Uc.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 12 Sampling part 17 Processing part S1 AC signal A Instantaneous value Ac Instantaneous value Aj Instantaneous value B Upper limit C Lower limit Nc Acquisition number Nj Acquisition number Ta period Ts Sampling period Uc Comparison object Uj Determination object

Claims (6)

A sampling unit that executes a sampling process for acquiring an instantaneous value of the input AC signal at a predetermined sampling period;
The AC signal for one or more cycles is defined as a determination target, and the AC signals for the same number of cycles as the determination target input earlier in time than the determination target are defined as comparison targets, and the determination An upper limit value obtained by adding a predetermined addition value to the instantaneous value of the comparison target corresponding to the instantaneous value of the target, a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value, and the determination target A measurement device comprising a processing unit that compares a instantaneous value and executes a determination process for determining pass / fail for the determination target based on the comparison result,
The processing unit, when the acquisition number of the instantaneous value of the comparison target acquired by the sampling process is different from the acquisition number of the instantaneous value of the determination target acquired by the sampling process, Based on the instantaneous value acquired by the sampling process in one of the determination targets, an interpolation formula for the one is specified, and the same number of instantaneous values as the number of acquisitions of the other comparison target and the determination target are determined. A measurement apparatus that performs an interpolation process calculated from the interpolation formula and executes the determination process using the instantaneous value calculated by the interpolation process and the instantaneous value acquired by the sampling process in the other. A sampling unit that executes a sampling process for acquiring an instantaneous value of the input AC signal at a predetermined sampling period;
The AC signal for one or more cycles is defined as a determination target, and the AC signals for the same number of cycles as the determination target input earlier in time than the determination target are defined as comparison targets, and the determination An upper limit value obtained by adding a predetermined addition value to the instantaneous value of the comparison target corresponding to the instantaneous value of the target, a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value, and the determination target A measurement device comprising a processing unit that compares a instantaneous value and executes a determination process for determining pass / fail for the determination target based on the comparison result,
The processing unit specifies each interpolation formula for the comparison target and the determination target based on the instantaneous value acquired by the sampling processing, and also determines the instantaneous value of the comparison target and the instantaneous value of the determination target. A measuring device that performs an interpolation process for calculating the same number of each from the interpolation formulas, and executes the determination process using an instantaneous value calculated by the interpolation process. The sampling unit acquires the instantaneous value as an integer value in the sampling process,
The processing unit converts the instantaneous value obtained by the sampling processing from an integer value to a floating point format, specifies the interpolation formula, calculates the floating point format instantaneous value from the interpolation formula, and calculates 3. The measuring apparatus according to claim 1, wherein an instantaneous value is converted from a floating point format to an integer value, and the upper limit value and the lower limit value are compared with the instantaneous value of the converted integer value.   The measuring apparatus according to claim 1, wherein a second-order or higher-order interpolation equation is specified as the interpolation equation. Perform sampling processing to acquire the instantaneous value of the input AC signal at a predetermined sampling period,
The AC signal for one or more cycles is defined as a determination target, and the AC signals for the same number of cycles as the determination target input earlier in time than the determination target are defined as comparison targets, and the determination An upper limit value obtained by adding a predetermined addition value to the instantaneous value of the comparison target corresponding to the instantaneous value of the target, a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value, and the determination target A determination method for performing a determination process for comparing the instantaneous value and determining the quality of the determination target based on the comparison result,
One of the comparison object and the determination object when the acquisition number of the instantaneous value of the comparison object acquired by the sampling process is different from the acquisition value of the instantaneous value of the determination object acquired by the sampling process The interpolation formula for one of the two is specified based on the instantaneous value acquired by the sampling processing in, and the same number of the instantaneous values as the other acquisition numbers of the comparison target and the determination target are calculated from the interpolation formula A determination method of performing the determination process using the instantaneous value calculated by the interpolation process and the instantaneous value acquired by the sampling process on the other side. Perform sampling processing to acquire the instantaneous value of the input AC signal at a predetermined sampling period,
The AC signal for one or more cycles is defined as a determination target, and the AC signals for the same number of cycles as the determination target input earlier in time than the determination target are defined as comparison targets, and the determination An upper limit value obtained by adding a predetermined addition value to the instantaneous value of the comparison target corresponding to the instantaneous value of the target, a lower limit value obtained by subtracting a predetermined subtraction value from the instantaneous value, and the determination target A determination method for performing a determination process for comparing the instantaneous value and determining the quality of the determination target based on the comparison result,
Based on the instantaneous value acquired by the sampling process, the interpolation formulas for the comparison target and the determination target are specified, and the instantaneous value of the comparison target and the instantaneous value of the determination target are equal to each other. A determination method of performing an interpolation process calculated from each of the interpolation formulas, and executing the determination process using an instantaneous value calculated by the interpolation process.

Images