JP2015111064A - Quality evaluation method, quality evaluation device, and quality evaluation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of evaluating whether a first product and a second product of the same kind have substantially the same quality or not.SOLUTION: Whether a workpiece Wa (a first product) and a workpiece Wb (a second product) of the same kind have substantially the same quality or not is evaluated by evaluating whether the workpiece Wa and the workpiece Wb have substantially the same quality or not on the basis of a frequency fak of a peak in each predetermined frequency band of vibration transmission characteristics of the workpiece Wa and a frequency fbk of a peak in each predetermined frequency band of the vibration transmission characteristics of the workpiece Wb. The vibration transmission characteristics is a ratio between a frequency spectrum of vibration in a first position of the workpiece W (product) vibrated by a piezo vibrator 5 (a vibration source) and a frequency spectrum of vibration in a second position located farther from the piezo vibrator 5 than the first position, in the workpiece W.

Description

  The present invention relates to a quality evaluation method, a quality evaluation apparatus, and a quality evaluation program.

  As this kind of technology, Patent Document 1 finds a product type of an unknown product by comparing the frequency distribution pattern of an unknown product as a product of unknown product type with the frequency distribution pattern of a known product as a product of known product type. The technology is disclosed. Here, the “frequency distribution pattern” is a frequency analysis of voltage waveform data obtained by exciting a product to freely vibrate and converting the vibration (mechanical displacement) into a voltage value. According to Patent Document 1, when there is a subtle difference in shape between an unknown product and a known product, or when the unknown product and the known product have the same shape but the material is different, the frequency distribution pattern of the unknown product is known. There is always a difference between the frequency distribution patterns of products.

JP 2003-14710 A

  By the way, with the aim of efficiently responding to demands in other countries and avoiding risks from natural disasters, etc., recently, decentralization of production areas of products of the same type has been promoted. And even if manufacturing sites are dispersed in this way, the quality of products of the same type is required to be substantially the same.

  However, the technique of the above-mentioned Patent Document 1 merely determines whether or not two products are of the same type, and it is not known whether the quality of the products of the same type is substantially the same.

  Therefore, an object of the present invention is to provide a technique for evaluating whether the first product and the second product of the same product have substantially the same quality.

A quality evaluation method for evaluating whether a first product and a second product of the same product have substantially the same quality, wherein a peak for each predetermined frequency band of vibration transfer characteristics of the first product And the first product and the second product have substantially the same quality based on the frequency of the second product and the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the second product. The vibration transfer characteristic is a frequency spectrum of vibration at a first position of a product excited by a vibration source and a position of the product farther from the vibration source than the first position. A quality evaluation method is provided that is a ratio of the frequency spectrum of the vibration at the second position. According to the above method, it is possible to evaluate whether the first product and the second product of the same product have substantially the same quality.
In a regression line between the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the first product and the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the second product Based on this, it is evaluated whether the first product and the second product have substantially the same quality.
Whether the first product and the second product have substantially the same quality is evaluated based on the regression coefficient and the constant term of the regression line.
When the regression coefficient of the regression line is within a predetermined regression coefficient range and the constant term of the regression line is within a predetermined constant term range, the first product and the second product are substantially Evaluate to have the same quality.
The plurality of products manufactured in the first manufacturing line that is the manufacturer of the first product and the plurality of products manufactured in the second manufacturing line that is the manufacturer of the second product. For any of the regression lines, when the regression coefficient of the regression line is within the predetermined regression coefficient range, and the constant term of the regression line is within the predetermined constant term range, the first production line The second production line evaluates to produce products having substantially the same quality. According to the above method, it is possible to evaluate whether the first production line and the second production line can produce products having substantially the same quality.
The predetermined regression coefficient range and the predetermined constant term range are determined based on the regression coefficient and the constant term of the regression line between the plurality of products manufactured in the first production line.
A quality evaluation apparatus that evaluates whether a first product and a second product of the same product have substantially the same quality, and acquires a vibration transfer characteristic of the first product. Acquisition means; second vibration transfer characteristic acquisition means for acquiring vibration transfer characteristics of the second product; peak frequency for each predetermined frequency band of the vibration transfer characteristics of the first product; Quality evaluation means for evaluating whether the first product and the second product have substantially the same quality based on the peak frequency for each of the predetermined frequency bands of the vibration transfer characteristics of the product The vibration transfer characteristic includes: a frequency spectrum of vibration at a first position of a product excited by a vibration source; and a position of the product farther from the vibration source than the first position. Frequency of vibration at some second position Spectrum, the ratio of the quality evaluation apparatus is provided. According to the above configuration, it is possible to evaluate whether the first product and the second product of the same product have substantially the same quality.
A quality evaluation program for causing a computer to execute the above-described quality evaluation method is provided.

  According to the present invention, it is possible to evaluate whether the first product and the second product of the same product have substantially the same quality.

It is a functional block diagram of a quality evaluation apparatus. (First embodiment) This is a quality evaluation flow. (First embodiment) It is a frequency spectrum of the output value of an input side vibration sensor. (First embodiment) It is a frequency spectrum of the output value of an output side vibration sensor. (First embodiment) It is a graph figure of a vibration transmission characteristic. (First embodiment) It is a graph for demonstrating the extraction method of the peak frequency of a vibration transfer characteristic. (First embodiment) It is a graph of a regression line. (First embodiment) It is a functional block diagram of a quality evaluation apparatus. (Second Embodiment) This is a quality evaluation flow. (Second Embodiment) This is a quality evaluation flow. (Second Embodiment) This is a quality evaluation flow. (Second Embodiment) It is a scatter diagram which shows the relationship between a regression coefficient and a constant term. (Second Embodiment) It is a scatter diagram which shows the relationship between a regression coefficient and a constant term. (Second Embodiment) It is a graph for demonstrating the extraction method of the peak frequency of a vibration transfer characteristic. It is a graph for demonstrating the extraction method of the peak frequency of a vibration transfer characteristic.

(First embodiment)
Hereinafter, the quality evaluation system 1 according to the first embodiment will be described with reference to FIGS.

  First, the configuration of the quality evaluation system 1 will be described with reference to FIG. The quality evaluation system 1 includes a work installation table 2, a vibration isolating rubber plate 3, a quality evaluation device 4, a piezoelectric vibrator 5, an input side vibration sensor 6, and an output side vibration sensor 7. Then, the workpiece W (product) is placed on the workpiece mounting table 2 via the vibration isolating rubber plate 3, the workpiece W is vibrated by the piezo-type vibrator 5, and the vibration of the workpiece W is measured by two input side vibration sensors. 6 and the output side vibration sensor 7 are used to evaluate the quality of the workpiece W. Specifically, it is as follows.

  The quality evaluation apparatus 4 is an apparatus that evaluates whether the work Wa (first product) and the work Wb (second product) as the work W of the same type have substantially the same quality. In the present embodiment, the workpiece Wa and the workpiece Wb are the same type, and both are acceptable products. Here, “accepted product” means a product that is manufactured according to the design document and does not become a defect in comparison with the design document. “Quality” includes both quality managed by the design document and quality not managed by the design document.

  The quality evaluation device 4 includes a CPU 8 (Central Processing Unit) as a central processing unit (not shown), a read / write RAM 9 (Random Access Memory), and a read-only ROM 10 (Read Only Memory). Then, the CPU 8 reads and executes the quality evaluation program stored in the ROM 10, so that the quality evaluation program causes the hardware such as the CPU 8 to be replaced with the vibration control unit 11, the vibration transfer characteristic calculation unit 12 (first vibration transfer characteristic). (Acquisition unit, second vibration transfer characteristic acquisition unit), peak frequency extraction unit 13, regression analysis unit 14, and quality evaluation unit 15 (quality evaluation unit).

  The piezo exciter 5 is attached to the work W and vibrates the work W. The piezo-type vibrator 5 is attached to the workpiece W at a position as far as possible from the vibration-proof rubber plate 3.

  The input-side vibration sensor 6 is attached to the workpiece W, converts the vibration of the workpiece W into a voltage signal, and outputs the voltage signal to the quality evaluation device 4. The input-side vibration sensor 6 is attached to the workpiece W in the vicinity (first position) of the piezoelectric vibrator 5.

  The output-side vibration sensor 7 is attached to the workpiece W, converts the vibration of the workpiece W into a voltage signal, and outputs the voltage signal to the quality evaluation device 4. The output-side vibration sensor 7 is attached to the workpiece W at a position (second position) far from the piezoelectric vibrator 5. That is, the input-side vibration sensor 6 is attached to the workpiece W at a position closer to the piezoelectric vibrator 5 than the output-side vibration sensor 7. The output-side vibration sensor 7 is attached to the workpiece W at a position farther from the piezoelectric vibrator 5 than the input-side vibration sensor 6.

  Next, the quality evaluation flow of the quality evaluation system 1 will be described with reference to FIGS.

  First, the workpiece Wa is placed on the workpiece mounting table 2 via the vibration isolating rubber plate 3, and the piezo-type vibrator 5, input side vibration sensor 6, and output side vibration sensor 7 are attached to the workpiece Wa (S100). The piezoelectric vibrator 5, the input side vibration sensor 6, and the output side vibration sensor 7 are all electrically connected to the quality evaluation device 4.

  Next, the vibration control unit 11 sweeps the workpiece Wa by operating the piezoelectric vibrator 5 (S110), and receives voltage signals from the input-side vibration sensor 6 and the output-side vibration sensor 7 for a predetermined time. The received voltage signal is stored in the RAM 9 (S120).

  Next, the vibration transfer characteristic calculation unit 12 calculates the vibration transfer characteristic of the workpiece Wa based on the voltage signal stored in the RAM 9 (S130). Here, the “vibration transfer characteristic” refers to the frequency spectrum of the vibration at the first position of the work W (product) vibrated by the piezoelectric vibrator 5 (vibration source) and the work W (product). It is a ratio with the frequency spectrum of the vibration in the second position, which is a position farther from the piezo-type vibrator 5 than the first position. Specifically, the “vibration transfer characteristic” is a frequency spectrum of vibration at the first position of the workpiece W (product) excited by the piezoelectric vibrator 5 (vibration source), and the workpiece W (product). The frequency spectrum of vibration at the second position, which is a position farther from the piezo vibrator 5 than the first position, is divided. In the present embodiment, the “first position” is a position closer to the piezo vibrator 5 than the “second position”. In short, the “vibration transfer characteristic” is obtained by dividing the frequency spectrum of the voltage signal output from the input side vibration sensor 6 by the frequency spectrum of the voltage signal output from the output side vibration sensor 7.

  Specifically, the vibration transfer characteristic calculation unit 12 performs a spectrum analysis on the voltage signal output from the input-side vibration sensor 6 and stored in the RAM 9, thereby performing a first analysis of the work Wa as shown in FIG. Obtain the frequency spectrum of the vibration at the position. In the graph of FIG. 3, the horizontal axis is frequency and the vertical axis is power value. Similarly, the vibration transfer characteristic calculation unit 12 performs spectrum analysis on the voltage signal output from the output-side vibration sensor 7 and stored in the RAM 9, so that the workpiece Wa at the second position as shown in FIG. Obtain the frequency spectrum of the vibration. In the graph of FIG. 4, the horizontal axis is frequency and the vertical axis is power value. And the vibration transfer characteristic calculating part 12 acquires the vibration transfer characteristic shown in FIG. 5 by remove | dividing the frequency spectrum of FIG. 4 by the frequency spectrum of FIG. In the graph of FIG. 5, the horizontal axis is the frequency, and the vertical axis is the transfer function.

  Next, the peak frequency extraction unit 13 extracts a peak frequency for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wa (S140). FIG. 6 is an enlarged view of the vibration transfer characteristic of FIG. In FIG. 6, a plurality of frequency bands Δf1, Δf2, Δf3, Δf4,..., Δfm−1, Δfm are shown with broken lines. 6 shows that the peak frequency in the frequency band Δf1 is fa1, the peak frequency in the frequency band Δf2 is fa2, the peak frequency in the frequency band Δf3 is fa3, the peak frequency in the frequency band Δf4 is fa4,. , The peak frequency in the frequency band Δfm−1 is shown as fam−1, and the peak frequency in the frequency band Δfm is shown as fam. The peak frequency extraction unit 13 stores the peak frequency fak in each frequency band Δfk (where k = 1, 2, 3, 4,..., M−1, m) in association with the frequency band Δfk in the RAM 9. To do.

  In the present embodiment, “a plurality of frequency bands Δfk” is obtained by visually confirming the peaks and valleys of the transfer function, and by setting the SN ratio of the transfer function to 3 or more as a guideline, the horizontal axis is set to about 40 to 50. It is determined by dividing.

  Next, the work Wb is placed on the work setting table 2 via the vibration isolating rubber plate 3, and the piezo-type vibrator 5, input side vibration sensor 6, and output side vibration sensor 7 are attached to the work Wb (S150).

  Next, the vibration control unit 11 sweeps the workpiece Wb by operating the piezoelectric vibrator 5 (S160), and receives voltage signals from the input-side vibration sensor 6 and the output-side vibration sensor 7 for a predetermined time. The received voltage signal is stored in the RAM 9 (S170).

  Next, the vibration transfer characteristic calculation unit 12 calculates the vibration transfer characteristic of the workpiece Wb based on the voltage signal stored in the RAM 9 (S180).

  Next, the peak frequency extraction unit 13 extracts the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wb (S190). At this time, the peak frequency extraction unit 13 applies a plurality of frequency bands Δf1, Δf2, Δf3, Δf4,..., Δfm−1, Δfm applied to the vibration transmission characteristics of the workpiece Wa to the vibration transmission characteristics of the workpiece Wb. Apply as is. The peak frequency in the frequency band Δf1 of the vibration transfer characteristic of the work Wb is fb1, the peak frequency in the frequency band Δf2 of the vibration transfer characteristic of the work Wb is fb2, and the peak frequency in the frequency band Δf3 of the vibration transfer characteristic of the work Wb. Is fb3, the peak frequency in the frequency band Δf4 of the vibration transfer characteristic of the work Wb is fb4,..., The peak frequency in the frequency band Δfm-1 of the vibration transfer characteristic of the work Wb is fbm−1, and the work Wb Let fbm be the peak frequency in the frequency band Δfm of the vibration transfer characteristics. The peak frequency extraction unit 13 stores the peak frequency fbk in each frequency band Δfk (where k = 1, 2, 3, 4,..., M−1, m) in the RAM 9 in association with the frequency band Δfk. To do.

  Next, the regression analysis unit 14 regresses the correlation between the peak frequency for each predetermined frequency band of the vibration transmission characteristic of the workpiece Wa and the peak frequency for each predetermined frequency band of the vibration transmission characteristic of the workpiece Wb. Analyze and calculate the regression coefficient (slope) and constant term (intercept) of the regression line (S200). FIG. 7 shows the regression line L obtained by the regression analysis unit 14. In the graph of FIG. 7, the horizontal axis represents the peak frequency of the workpiece Wa, and the vertical axis represents the peak frequency of the workpiece Wb. Each plot pk (where k = 1, 2, 3, 4,..., M−1, m) represents the peak frequency fak and the work Wb of the vibration transfer characteristic of the work Wa in the same frequency band Δfk. This is constituted by the peak frequency fbk of the vibration transfer characteristic.

  Then, based on the regression coefficient and constant term of the regression line L, the quality evaluation unit 15 evaluates whether the workpiece Wa and the workpiece Wb as the workpiece W of the same type have substantially the same quality (S210- S230). Specifically, when the regression coefficient of the regression line L is within a predetermined regression coefficient range and the constant term of the regression line L is within the predetermined constant term range (S210: YES), the quality evaluation unit 15 Then, it is evaluated that the workpiece Wa and the workpiece Wb as the workpiece W of the same type have substantially the same quality (S220). On the other hand, when the regression coefficient of the regression line L is not within the predetermined regression coefficient range, or when the constant term of the regression line L is not within the predetermined constant term range (S210: NO), the quality evaluation unit 15 is the same type. It is evaluated that the workpiece Wa and the workpiece Wb as a certain workpiece W do not have substantially the same quality (S230).

  Finally, the quality evaluation device 4 displays the evaluation result on a display screen such as an LCD (Liquid Crystal Display).

  Although the first embodiment has been described above, the first embodiment has the following features.

(1) Quality evaluation for evaluating whether the workpiece Wa (first product) and the workpiece Wb (second product), which are the same product, have substantially the same quality, is performed according to a predetermined vibration transmission characteristic of the workpiece Wa. Based on the peak frequency fak for each frequency band and the peak frequency fbk for each predetermined frequency band of the vibration transfer characteristic of the work Wb, it is evaluated whether the work Wa and the work Wb have substantially the same quality. Is done. However, the vibration transfer characteristic means that the frequency spectrum of vibration at the first position of the workpiece W (product) vibrated by the piezo-type vibrator 5 (vibration source) and the first position of the workpiece W are larger than those at the first position. It is a ratio with the frequency spectrum of the vibration in the 2nd position which is a position far from the piezo-type vibrator 5. According to the above method, it is possible to evaluate whether the work Wa and the work Wb which are the same product have substantially the same quality.
(2) Based on a regression line L between the peak frequency fak for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wa and the peak frequency fbk for each predetermined frequency band of the vibration transmission characteristic of the workpiece Wb. Then, it is evaluated whether the workpiece Wa and the workpiece Wb have substantially the same quality.
(3) Based on the regression coefficient and constant term of the regression line L, it is evaluated whether the workpiece Wa and the workpiece Wb have substantially the same quality.
(4) When the regression coefficient of the regression line L is within the predetermined regression coefficient range and the constant term of the regression line L is within the predetermined constant term range, the workpiece Wa and the workpiece Wb have substantially the same quality. Then evaluate.
(7) The quality evaluation device 4 that evaluates whether the workpiece Wa and the workpiece Wb of the same type have substantially the same quality is obtained by the vibration transfer characteristic calculation unit 12 (first vibration) that acquires the vibration transfer characteristic of the workpiece Wa. Transfer characteristic acquisition means), a vibration transfer characteristic calculation unit 12 (second vibration transfer characteristic acquisition means) for acquiring the vibration transfer characteristic of the workpiece Wb, and a peak frequency fak for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wa. And a quality evaluation unit 15 (quality evaluation means) for evaluating whether the workpiece Wa and the workpiece Wb have substantially the same quality based on the peak frequency fbk for each predetermined frequency band of the vibration transfer characteristics of the workpiece Wb. And). According to the above configuration, it is possible to evaluate whether the work Wa and the work Wb which are the same product have substantially the same quality.

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. Hereinafter, the present embodiment will be described with a focus on differences from the first embodiment, and overlapping descriptions will be omitted as appropriate.

  The quality evaluation apparatus 4 of the first embodiment evaluates whether the workpiece Wa (first product) and the workpiece Wb (second product) as the workpiece W of the same type have substantially the same quality. It was assumed to be a device. On the other hand, in the quality evaluation apparatus 4 of the present embodiment, the production line A (first production line) that is the manufacturer of the workpiece Wa and the production line B (second production line) that is the manufacturer of the workpiece Wb are as follows. This is an apparatus for evaluating whether or not a workpiece W having substantially the same quality is manufactured.

  As shown in FIG. 8, the quality evaluation program according to the present embodiment further causes hardware such as the CPU 8 to function as an evaluation reference generation unit 16 (evaluation reference generation means).

  Next, the quality evaluation flow of the quality evaluation system 1 will be described with reference to FIGS. When evaluating whether the production line A and the production line B produce the workpiece W having substantially the same quality using the quality evaluation apparatus 4, p pieces of workpieces Wa produced on the production line A are used. Q pieces of workpieces Wb manufactured in the manufacturing line B are prepared in advance. The same number may be sufficient as p and q, and a different number may be sufficient as them.

  As shown in FIG. 9, first, among the p number of workpieces Wa, the first workpiece Wa is placed on the workpiece mounting table 2 via the vibration isolating rubber plate 3, and the piezo-type vibrator 5 and the input side vibration sensor 6. The output-side vibration sensor 7 is attached to the workpiece Wa (S300).

  Next, the vibration control unit 11 sweeps the workpiece Wa by operating the piezoelectric vibrator 5 (S310), and receives voltage signals from the input-side vibration sensor 6 and the output-side vibration sensor 7 for a predetermined time. The received voltage signal is stored in the RAM 9 (S320).

  Next, the vibration transfer characteristic calculation unit 12 calculates the vibration transfer characteristic of the workpiece Wa based on the voltage signal stored in the RAM 9 (S330).

  Next, the peak frequency extraction unit 13 extracts the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wa (S340).

  Next, it is confirmed whether there is a next workpiece Wa (S350). When there is the next workpiece Wa (S350: YES), the next workpiece Wa is placed on the workpiece setting table 2 via the vibration isolating rubber plate 3, and the piezoelectric vibrator 5 and the input side vibration sensor 6 are output. The side vibration sensor 7 is attached to the workpiece Wa (S360), and the process returns to S310. On the other hand, if there is no next workpiece Wa (S350: NO), the process proceeds to S400.

  As shown in FIG. 10, in S400, the first workpiece Wb out of q workpieces Wb is first placed on the workpiece mounting table 2 via the vibration isolating rubber plate 3, and the piezoelectric vibrator 5 and the input side are placed. The vibration sensor 6 and the output side vibration sensor 7 are attached to the workpiece Wb (S400).

  Next, the vibration control unit 11 sweeps the workpiece Wb by operating the piezo exciter 5 (S410) and outputs voltage signals from the input side vibration sensor 6 and the output side vibration sensor 7 for a predetermined time. The received voltage signal is stored in the RAM 9 (S420).

  Next, the vibration transfer characteristic calculation unit 12 calculates the vibration transfer characteristic of the workpiece Wb based on the voltage signal stored in the RAM 9 (S430).

  Next, the peak frequency extraction unit 13 extracts a peak frequency for each predetermined frequency band of the vibration transfer characteristic of the workpiece Wb (S440).

  Next, it is confirmed whether there is a next workpiece Wb (S450). When there is the next workpiece Wb (S450: YES), the next workpiece Wb is placed on the workpiece installation table 2 via the vibration isolating rubber plate 3, and the piezoelectric vibrator 5 and the input side vibration sensor 6 are output. The side vibration sensor 7 is attached to the workpiece Wb (S460), and the process returns to S410. On the other hand, if there is no next workpiece Wb (S450: NO), the process proceeds to S500.

As shown in FIG. 11, in S500, the regression analysis unit 14 performs regression analysis on the correlation between peak frequencies fak for each predetermined frequency band of the vibration transfer characteristics of the p workpieces Wa, and the regression coefficient of the regression line (Slope) and constant term (intercept) are calculated (S500). In the present embodiment, p workpieces Wa are prepared. Therefore, the regression analysis unit 14 performs the above regression analysis _p C ₂ = (p × (p−1)) / (2 × 1) times. That is, the regression analysis unit 14 performs regression analysis on the correlation between the peak frequency fak for each predetermined frequency band of the vibration transfer characteristics of the p pieces of workpieces Wa by a brute force method. For example, when 45 workpieces Wa are prepared, the regression analysis unit 14 performs the regression analysis 990 times. The _p C ₂ regression coefficients (slopes) and _p C ₂ constant terms (intercepts) thus obtained are shown in a scatter diagram form in FIG. In FIG. 12, a set of regression coefficient (slope) and constant term (intercept) obtained from one regression line corresponds to one plot.

Next, the evaluation criterion generation unit 16 generates a regression coefficient range as a criterion for evaluating substantial quality identity based on the _p C _two regression coefficients (slopes) (S510). Specifically, since the _p C ₂ pieces of the regression coefficients is obtained as a sample of the regression coefficients, criteria generating unit 16 estimates the population statistics stochastically regression coefficients, for example, a positive population The range of minus 3σ is set as the regression coefficient range. Similarly, the evaluation criterion generating unit 16 generates a constant term range as a criterion for evaluating the substantial quality identity based on the _p C _two constant terms (intercepts) (S510). Specifically, since _p C ₂ constant terms are obtained as constant term samples, the evaluation criterion generation unit 16 estimates the population of constant terms statistically, for example, plus the population plus A range that is minus 3σ is set as the constant term range. The regression coefficient range and the constant term range thus set are indicated by a reference frame R in FIG.

  Next, the regression analysis unit 14 determines the peak frequency fak for each predetermined frequency band of the vibration transfer characteristics of the p workpieces Wa and the peak frequency for each predetermined frequency band of the vibration transfer characteristics of the q workpieces Wb. The correlation with fbk is subjected to regression analysis, and the regression coefficient (slope) and constant term (intercept) of the regression line are calculated (S520). In the present embodiment, p workpieces Wa are prepared and q workpieces Wb are prepared. Therefore, the regression analysis unit 14 performs the above regression analysis p × q times. That is, the regression analysis unit 14 determines the peak frequency fak for each predetermined frequency band of the vibration transfer characteristics of the p workpieces Wa and the peak frequency fbk for each predetermined frequency band of the vibration transfer characteristics of the q workpieces Wb. A regression analysis is performed on the correlation between and. For example, when 45 workpieces Wa are prepared and 48 workpieces Wb are prepared, the regression analysis unit 14 executes the regression analysis 2160 times. The thus obtained p × q regression coefficients (slopes) and p × q constant terms (intercepts) are shown in a scatter diagram form in FIG. In FIG. 13, a set of regression coefficient (slope) and constant term (intercept) obtained from one regression line corresponds to one plot.

  Next, the quality evaluation unit 15 is a manufacturing line A (first manufacturing line) that is a manufacturer of the workpiece Wa and a manufacturer of the workpiece Wb based on the regression coefficients and constant terms of the p × q regression lines. It is evaluated whether the production line B (second production line) produces workpieces W having substantially the same quality (S530-S550). Specifically, when the regression coefficients of all regression lines are within a predetermined regression coefficient range and the constant terms of all regression lines are within the predetermined constant term range (S530: YES), the quality evaluation unit 15 evaluates that the production line A, which is the manufacturer of the workpiece Wa, and the production line B, which is the manufacturer of the workpiece Wb, produce the workpiece W having substantially the same quality (S540). In other words, in this case (S530: YES), the quality evaluation unit 15 evaluates that the work Wa on the production line A and the work Wb on the production line B have substantially the same quality (S540). On the other hand, if the regression coefficient of any regression line is outside the predetermined regression coefficient range, or the constant term of any regression line is outside the predetermined constant term range (S530: NO), the quality evaluation unit 15 Evaluates that the production line A, which is the manufacturer of the workpiece Wa, and the production line B, which is the manufacturer of the workpiece Wb, cannot manufacture the workpiece W having substantially the same quality (S550). In other words, in this case (S530: NO), the quality evaluation unit 15 evaluates that the work Wa on the production line A and the work Wb on the production line B do not have substantially the same quality (S550).

  Finally, the quality evaluation device 4 displays the evaluation result on a display screen such as an LCD (Liquid Crystal Display).

  Although the second embodiment has been described above, the second embodiment has the following features.

(5) A plurality of products manufactured on the manufacturing line A (first manufacturing line) that is the manufacturer of the workpiece Wa and a plurality of products manufactured on the manufacturing line B (second manufacturing line) that is the manufacturer of the workpiece Wb For any of the regression lines between products, when the regression coefficient of the regression line is within the predetermined regression coefficient range and the constant term of the regression line is within the predetermined constant term range, production line A and production line B evaluates to produce a workpiece W having substantially the same quality. According to the above method, it is possible to evaluate whether the production line A and the production line B can produce the workpiece W having substantially the same quality.
(6) The predetermined regression coefficient range and the predetermined constant term range are determined based on the regression coefficient and the constant term of the regression line between the plurality of workpieces W manufactured on the production line A.

  Each said embodiment can be changed as follows, for example.

  In the first embodiment and the second embodiment, the “plurality of frequency bands” indicates that the SN ratio of the transfer function is 3 or more while visually confirming the peaks and valleys of the transfer function. Is determined by dividing it into about 40-50. However, instead of this, as shown in FIG. 14, it may be determined by dividing the horizontal axis into about 40 to 50 at equal intervals. Alternatively, as shown in FIG. 15, when the natural frequency of the workpiece W is known, it may be determined by dividing the horizontal axis by the natural value and its order component.

  In the above example, the quality assessment program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. Further, the quality evaluation program may be supplied to the computer by various types of temporary computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the quality evaluation program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

DESCRIPTION OF SYMBOLS 1 Quality evaluation system 2 Work installation stand 3 Anti-vibration rubber plate 4 Quality evaluation apparatus 5 Piezo-type vibrator 6 Input side vibration sensor 7 Output side vibration sensor 11 Vibration control part 12 Vibration transfer characteristic calculation part 13 Peak frequency extraction part 14 Return Analysis unit 15 Quality evaluation unit 16 Evaluation standard generation unit
L regression line
A Production line
B Production line
W Work
Wa work
Wb work

Claims (8)

A quality evaluation method for evaluating whether a first product and a second product of the same type have substantially the same quality,
Based on the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the first product and the peak frequency for the predetermined frequency band of the vibration transfer characteristic of the second product, the first Evaluating whether the second product and the second product have substantially the same quality,
The vibration transfer characteristics include a frequency spectrum of vibration at a first position of a product excited by a vibration source, and a second position of the product that is farther from the vibration source than the first position. Is the ratio of the frequency spectrum of vibration at
Quality evaluation method. The quality evaluation method according to claim 1,
In a regression line between the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the first product and the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the second product Based on whether the first product and the second product have substantially the same quality,
Quality evaluation method. The quality evaluation method according to claim 2,
Evaluating whether the first product and the second product have substantially the same quality based on a regression coefficient and a constant term of the regression line;
Quality evaluation method. The quality evaluation method according to claim 3,
When the regression coefficient of the regression line is within a predetermined regression coefficient range and the constant term of the regression line is within a predetermined constant term range, the first product and the second product are substantially Evaluate that they have the same quality,
Quality evaluation method. The quality evaluation method according to claim 4,
The plurality of products manufactured in the first manufacturing line that is the manufacturer of the first product and the plurality of products manufactured in the second manufacturing line that is the manufacturer of the second product. For any of the regression lines, when the regression coefficient of the regression line is within the predetermined regression coefficient range, and the constant term of the regression line is within the predetermined constant term range, the first production line And the second production line evaluates to produce products having substantially the same quality,
Quality evaluation method. The quality evaluation method according to claim 5,
The predetermined regression coefficient range and the predetermined constant term range are determined based on the regression coefficient and the constant term of the regression line between the plurality of products manufactured in the first production line.
Quality evaluation method. A quality evaluation device that evaluates whether the first product and the second product of the same product have substantially the same quality,
First vibration transfer characteristic acquisition means for acquiring vibration transfer characteristics of the first product;
Second vibration transfer characteristic acquisition means for acquiring the vibration transfer characteristic of the second product;
Based on the peak frequency for each predetermined frequency band of the vibration transfer characteristic of the first product and the peak frequency for the predetermined frequency band of the vibration transfer characteristic of the second product, Quality evaluation means for evaluating whether the first product and the second product have substantially the same quality;
With
The vibration transfer characteristics include a frequency spectrum of vibration at a first position of a product excited by a vibration source, and a second position of the product that is farther from the vibration source than the first position. Is the ratio of the frequency spectrum of vibration at
Quality evaluation device. On the computer,
A quality evaluation program for executing the quality evaluation method according to claim 1.

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