JPS6170473A - Waveform analyzer - Google Patents

Abstract

PURPOSE:To decide the quality of a product rapidly and precisely after analyzing its waveform by reading the waveform of a product to be measured and comparing the waveform with a reference waveform obtained by averaging the waveforms of plural products to be decided as high quality. CONSTITUTION:The waveforms of plural electric signals indicating the characteristics of products decided as high quality are previously inputted to a computer 6 through a change-over switch 3 and an A/D converter 5 and stored in a high quality product waveform reading RAM12. The computer 6 calculates the average value of the high quality product waveforms and then stores the upper and lower limits of waveforms in a high quality product limit range, the high quality product limit range of the upper and lower limits of leading values, the high quality produce limit range of the upper and lower limit of time required up to zero crossing, the high quality product limit range of the upper and lower limits of effective values obtained by dividing the whole swept waveforms by the number of divided areas in a reference waveform RAM13. Then, the measured electric signal waveform 2 indicating the characteristics of a product to be tested is inputted to the computer 6 through an A/D converter 5 after turning the change-over switch 3, stored in a measured waveform RAM14 and compared with the reference waveform stored in the RAM13. Signals exceeding the high quality product limit range indicating the upper and lower limits are counted up in each function, and when the counted value reaches a fixed value, the product is decided as a defective one.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that analyzes unique electrical signal waveforms of electrical components, mechanical devices, etc., and determines the quality of these devices.

Conventionally, waveform analysis devices have mainly been used to store electrical signal waveforms, visually observe them, and calculate waveform signals.

Once a waveform is read into the storage device, vector operations on the waveform such as 7-lier operation, excursion/integral operation, and correlation operation are performed, and the values of these operation results are displayed, as well as the original waveform and the result of the operation. It displayed and analyzed waveforms.

In order to be applied to product inspection, the present invention reads the waveforms of multiple products judged to be non-defective, averages them, and uses them as a reference waveform, and then reads the waveform of the product under test and compares the waveform with the reference waveform. By performing comparison calculations such as coincidence degree calculation, peak value calculation, frequency component calculation, and effective value calculation, it is possible not only to simply calculate waveform data but also to quickly and accurately judge the quality of the product after waveform analysis. This provides a method that allows you to do so.

An embodiment of the present invention will be described below with reference to the drawings. I
:fS1 diagram is a functional block diagram of the present invention, in which the electric signal waveform (rjS
Approximately 30 data of the analog waveform (Fig. 2) is input to the A/D converter (5) via the changeover switch (3) and amplifier (4).

The A/D converter (5) operates at fixed time intervals (approximately 100 ns ~
The computer (6) converts it into a dinotal signal every 1 second).
Enter. The computer (6) sequentially stores these non-defective electrical signal waveforms in the non-defective waveform reading RAM (12). When the import of non-defective product data is completed, the computer (6
) is obtained by adding the values of approximately 30 data at the same time (for example, 1+) shown in Figure 2 from the good waveform reading RAM (12), and then dividing by the number of added data to obtain the simple average value, and calculating the value for each time. Set the upper limit value setting switch (15
) is added to the upper limit reference waveform and the reference waveform RA
M (13), and the value obtained by subtracting the value of the lower limit value setting switch (16) from the value at each time is stored in the lower limit reference waveform RAM (14). Similarly, for peak value determination (Figure 4), the peak value upper/lower limit setting switch (1
The value read from 7) is added to the upper limit peak value, and the value subtracted from it is stored as the lower limit peak value in the reference waveform RAM (13). To determine the time to zero cross (Figure 5), the upper limit time is calculated by adding the value of the time upper/lower limit setting switch (18) to zero cross to the time it takes for the waveform value to become zero for the first time after the start of the waveform sweep. , the subtracted value is stored in the reference waveform RAM (13) as the lower limit time. For waveform effective value determination (Figure 6), the area of the entire waveform after waveform sweep is:
(PtS6 figure) (b) S++ S2+S3+
S4 + SS, the value obtained by adding the value of the waveform effective value upper/lower limit setting switch (19) to this integral value is the upper limit effective value, and the value subtracted is the lower limit effective value and is stored in the reference waveform RAM.
(13). With respect to the reference waveform created in this way, the electrical signal waveform to be measured (2), which indicates the characteristics of the product to be inspected, is switched to 6 inches (3), and the analog waveform is converted to A via an amplifier (4). /D converter (5). A
The /D converter (5) converts the good electrical signal waveform (1) read in when creating the reference waveform into a dinotal signal at the same time interval and inputs it to the computer (6). The computer (6) stores these digitized electrical signal waveforms to be measured (2) in the waveform to be measured RAM (14), and sequentially stores the upper limit reference waveform (No. 1) stored in the reference waveform RAM (13). Figure 3) (a) (1), lower limit reference waveform (f
Fig. fi3> (a) Compare with (3), and when the electrical signal waveform to be measured (2) exceeds these upper and lower limit values, the waveform at that time is determined to be defective.

If n failure determinations occur consecutively, or if the total number of failure determinations is m or more, the product under test is determined to have a characteristic waveform defect. Similarly, when the peak value is 1/1 constant, the electrical signal waveform to be measured (2) is stored in the waveform to be measured RAM (14) by the same means.
After being stored in the reference waveform RAM (13), the first peak value after the start of the sweep of the measured waveform (2) and the reference waveform RAM (13),
The lower limit peak values are compared, and if a certain number or more exceed the upper and lower limit values, the product to be measured is determined to have a defective peak value. The time to zero cross is determined using the same means as measured waveform RAM.
Compare the time until the waveform value becomes zero for the first time after the start of the sweep of the measured waveform (2) stored in (14), and the upper and lower limit times, and a certain number or more exceed the upper and lower limit values. In this case, the product under test is determined to be defective in the time to zero cross. Waveform effective value judgment is performed using the same means as measured waveform RAM (14)
Compare the upper and lower limit effective values with the sum of the area of all waveforms after the start of the sweep of the measured waveform (2) stored in It is determined that the effective value is poor. If any one of the characteristic waveform defects, peak value defects, time to zero cross defects, and waveform effective value defects that are determined to be defective exists, the product to be measured is determined to be defective.

As a modification of the present invention, the waveform sweep method includes an X-Y sweep waveform characteristic test in which current is applied horizontally and voltage is applied vertically;
Calculation methods include correlation analysis, similarity calculation using least squares method,
It is also possible to include high-speed 7-lier calculations that perform frequency analysis of waveforms.

Further, a function selection switch may be provided that can individually turn ON/OFF functions such as characteristic waveform 1, peak value, time to zero cross, and waveform effective value. Regarding the determination of the peak value and the time to zero cross, it is also possible to perform measurements using data other than the first peak value or the time until the first zero cross after the waveform sweep. Even if you use electronic circuits for the same purpose without using a computer,
The same functions can be developed.

As described above, according to the present invention, product characteristic waveforms can be determined quickly and accurately by various means, and an effective product characteristic testing method is provided.

[Brief explanation of drawings]

FIG. 1 shows the configuration of the present invention. noji block, fj
Figure S2 is an electrical signal waveform showing the product characteristics, and Figure ptS3 is an explanatory diagram of characteristic waveform upper and lower limits +7 limit judgment (,)
is a reference waveform and indicates a non-defective product judgment state, (b) is a non-defective waveform with small noise added, (c) and (d) indicate a characteristic waveform defect, and Fig. 3 shows a peak value judgment state. (a) shows the reference waveform and non-defective product judgment state, (b) and (c) show peak value failure, flS5 diagram shows the time judgment until zero cross (a)
6 shows the reference waveform and non-defective product judgment state, (b) and (c) show a defective time judgment until zero cross, FIG. 6 shows the waveform effective value judgment, (a) shows the reference waveform and non-defective product judgment state, (b), (c)
7 shows a waveform effective value judgment failure. −
70 is a chart diagram of a program 2 representing a determination processing function in a computer; FIG. A Yuto O Non-receipt of money A source of insult to Itenfuchizute Be- Procedural amendment f (method) February 26, 1985 Special FF Agency 11! Tono Showa 60
Submitted on February 25, 1982, Incident Indication: 1982 Patent G No. 192392 2, Name of Invention: Waveform Analyzer Z 3, Person making the correction Telephone number: (045) 481-2022 Fite Yuri Co., Ltd. System 4, Name of agent (name) @5, Date of amendment order (shipment date) January 29, 19856,
Subject of amendment (1) Column for the seal of the applicant in document H (2) Column 7 for a brief explanation of the blueprint drawing, Contents of the amendment

Claims (1)

[Claims] Analyze signal waveforms such as voltage and current that change over time.
After reading into a computer via a D converter, the characteristic waveforms of multiple products that are known to be good are read in using a device with storage, calculation, and judgment functions. Calculate the average value of and use it as the reference waveform. A means for setting the upper and lower limits of the acceptable limit range waveform around the reference waveform to be narrow at the start of the waveform sweep, and to remain the same or wider over time, and to set the upper and lower limits of the peak value of the first waveform after the waveform sweep. a means for determining the upper and lower limits of the time until the first zero crossing after a waveform sweep; and a means for determining the upper and lower limits of the effective value for which the effective value is the area integral of the entire swept waveform. In addition to setting the acceptable product limit range, a device is installed for each function to count the signals that exceed the upper and lower non-defective product limit ranges, and when a certain number is reached, it can be determined as defective, and it is also possible to decide whether to use these functions. A method in which a selection switch is provided to determine whether or not the product is defective, and if a defective determination signal is present in any one of the function-selected determination result outputs, the product under test is determined to be defective.