Inspecting method of elastic body, inspecting apparatus thereof, and dimension predicting program thereof

• US 7,424,827 B2
• Filed: 04/27/2005
• Issued: 09/16/2008
• Est. Priority Date: 04/27/2004
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yamada, Tomohiro, Hatta, Tetsuya, Komazawa, Masato, Nehagi, Takatoshi
• Primary Examiner(s): Williams; Hezron E.
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US11/115,981
• Publication Number:
  US 20050284224A1
• Time in Patent Office: 1,238 Days
• Field of Search: 736/49, 738/625.9, 737/02, 735/17.AV, 737/04, 735/041.2, 735/040.2, 735/040.3, 735/041.4, 735/143.4, 735/79, 735/82, 735/97, 736/02, 737/17
• US Class Current: 73/579
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: H01H 2057/006 Micromechanical piezoelectric relay
• CPC Class Codes: H10N 30/2047 Membrane type

Abstract

In an inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, the frequency response characteristics is picked up when a vibration is given to the piezoelectric/electrostrictive actuator, and the amount of displacement of the piezoelectric/electrostrictive actuator is predicted by the frequency response characteristics. The piezoelectric/electrostrictive actuator is precisely inspected without dissolution and destruction and without actual driving as a product.

Claims

1. An inspecting method of an elastic body in a structure having two or more elastic bodies, said method comprising:

observing a frequency response characteristic of said two or more elastic bodies when a vibration is applied to said structure having two or more elastic bodies; and

predicting a dimension of said two or more elastic bodies based on said frequency response characteristic;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

2. An inspecting method of an elastic body according to claim 1, wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PRDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

3. An inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive actuator when a vibration is applied to said piezoelectric/electrostrictive actuator; and

predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said frequency response characteristic;

wherein said frequency response characteristic is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

4. An inspecting method of a piezoelectric/electrostrictive actuator according to claim 3, wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of other degrees and at least one of resonant frequencies of other degrees.

5. An inspecting method of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said frequency response characteristic;

wherein said frequency response characteristic is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

6. An inspecting method of a piezoelectric/electrostrictive sensor according to claim 5, wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

7. An inspecting apparatus of an elastic body in a structure having two or more elastic bodies, said apparatus comprising:

means for observing a frequency response characteristic of said two or more elastic bodies when a vibration is applied to said structure having said two or more elastic bodies; and

means for predicting a dimension of said two or more elastic bodies based on said frequency response characteristic;

wherein said frequency response characteristic is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

8. An inspecting apparatus of an elastic body according to claim 7, wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and resonant frequencies of other degrees.

9. An inspecting apparatus of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive actuator when a vibration is applied to said piezoelectric/electrostrictive actuator; and

means for predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said frequency response characteristic;

wherein said frequency response characteristic is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

10. An inspecting apparatus of a piezoelectric/electrostrictive actuator according to claim 9, wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

11. An inspecting apparatus of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

means for predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said frequency response characteristic;

wherein said frequency response characteristic is a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees.

12. An inspecting apparatus of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

means for predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said frequency response characteristic;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

13. A dimension predicting program, for predicting a dimension of an elastic body in a structure having two or more of elastic bodies, provided on a computer readable medium to enable a computer to function as:

means for inputting a measurement value of a frequency response characteristic of a structure having two or more of elastic bodies whose predicted dimension is calculated;

means for obtaining a predicted dimension of said elastic body of said structure based on a calculating formula of the predicted dimension; and

means for outputting thus obtained predicted dimension of said elastic body of said structure to one of a CRT, printer, and a selector device that uses the obtained data to determine whether the structure is defective and selects defective structures for removal.

14. A prediction program, for predicting an amount of displacement of a piezoelectric/electrostrictive actuator for predicting an amount of displacement of said piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, provided on a computer readable medium to enable a computer to function as:

means for inputting a frequency response characteristic of said piezoelectric/electrostrictive actuator whose predicted amount of displacement is calculated;

means for obtaining a predicted amount of displacement of said piezoelectric/electrostrictive actuator based on a calculating formula of the predicted amount of displacement; and

means for outputting thus obtained predicted amount of displacement of said piezoelectric/electrostrictive actuator to one of a CRT, printer, and a selector device that uses the obtained data to determine whether the structure is defective and selects defective structures for removal.

15. A prediction program, for predicting a detecting sensitivity of a piezoelectric/electrostrictive sensor, provided on a computer readable medium to enable a computer to function as:

means for inputting a frequency response characteristic of a piezoelectric/electrostrictive sensor whose predicted detecting sensitivity is to be calculated;

means for obtaining a predicted detecting sensitivity of said piezoelectric/electrostrictive sensor based on a calculating formula of said detecting sensitivity; and

means for outputting thus obtained predicted detecting sensitivity of said piezoelectric/electrostrictive sensor to one of a CRT, printer, and a selector device that uses the obtained data to determine whether the structure is defective and selects defective structures for removal.

16. An inspecting method of an elastic body in a structure having two or more elastic bodies, said method comprising:

observing a frequency response characteristic of said two or more elastic bodies of said structure when a vibration is applied to said structure; and

predicting a dimension of said two or more elastic bodies of said structure based on said observed frequency characteristic of said two or more elastic bodies of said structure using data representing a relationship between a frequency response characteristic of a standard body having at least one known dimension and said dimension of said standard body as a vibration is applied thereto;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

17. An inspecting method of an elastic body in a structure having two or more elastic bodies, said method comprising:

observing a frequency response characteristic of said two or more elastic bodies of said structure when a vibration is applied to said structure; and

predicting a dimension of said two or more elastic bodies of said structure based on said observed frequency characteristic of said two or more elastic bodies of said structure using data representing a relationship between a frequency response characteristic of a standard body having at least one known dimension and said dimension of said standard body as a vibration is applied thereto;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

18. An inspecting apparatus of an elastic body in a structure having two or more elastic bodies, said apparatus comprising:

means for observing a frequency response characteristic of said two or more elastic bodies of said structure when a vibration is applied to said structure; and

means for predicting a dimension of said two or more elastic bodies of said structure based on said observed frequency response characteristic of said two or more elastic bodies of said structure using data representing a relationship between an observed frequency response characteristic of a standard elastic body having at least one known dimension and said dimension of said standard body as a vibration is applied thereto;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

19. An inspecting apparatus of an elastic body in a structure having two or more elastic bodies, said apparatus comprising:

means for observing a frequency response characteristic of said two or more elastic bodies of said structure when a vibration is applied to said structure; and

means for predicting a dimension of said two or more elastic bodies of said structure based on said observed frequency response characteristic of said two or more elastic bodies of said structure using data representing a relationship between an observed frequency response characteristic of a standard elastic body having at least one known dimension and said dimension of said standard body as a vibration is applied thereto;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

20. An inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive actuator as a vibration is applied to said piezoelectric/electrostrictive actuator; and

predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said observed frequency response characteristics of said piezoelectric/electrostrictive actuator using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

21. An inspecting method of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive actuator as a vibration is applied to said piezoelectric/electrostrictive actuator; and

predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said observed frequency response characteristics of said piezoelectric/electrostrictive actuator using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKLRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

22. An inspecting apparatus of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive actuator when a vibration is applied to said piezoelectric/electrostrictive actuator; and

means for predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said observed frequency response characteristic of said piezoelectric/electrostrictive actuator using data representing a relationship between an observed frequency response characteristic of a standard body having at least one known dimension and said dimension of said standard body as a vibration is applied to the standard body;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

23. An inspecting apparatus of a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive actuator when a vibration is applied to said piezoelectric/electrostrictive actuator; and

means for predicting an amount of displacement of said piezoelectric/electrostrictive actuator based on said observed frequency response characteristic of said piezoelectric/electrostrictive actuator using data representing a relationship between an observed frequency response characteristic of a standard body having at least one known dimension and said dimension of said standard body as a vibration is applied to the standard body;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

24. An inspecting method of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

predicting a detection sensitivity of said piezoelectric/electrostrictive sensor based on said observed frequency response characteristic of said piezoelectric/electrostrictive sensor using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

25. An inspecting method of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said method comprising:

observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

predicting a detection sensitivity of said piezoelectric/electrostrictive sensor based on said observed frequency response characteristic of said piezoelectric/electrostrictive sensor using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.

26. An inspecting apparatus of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

means for predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said observed frequency characteristic of said piezoelectric/electrostrictive sensor using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one of the characteristics selected from the group consisting of a combination of a resonance frequency Fx of one degree and at least one of resonant frequencies Fy of other degrees, one or more of frequency ratios FRxy wherein FRxy is Fy/Fx obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies of other degrees and one or more of frequency differences FDxy (wherein FDxy is Fy-Fx) obtained by using said resonance frequency Fx of one degree and said at least one of resonant frequencies degrees.

27. An inspecting apparatus of a piezoelectric/electrostrictive sensor having a piezoelectric/electrostrictive element and two or more electrodes, said apparatus comprising:

means for observing a frequency response characteristic of said piezoelectric/electrostrictive sensor when a vibration is applied to said piezoelectric/electrostrictive sensor; and

means for predicting a detecting sensitivity of said piezoelectric/electrostrictive sensor based on said observed frequency characteristic of said piezoelectric/electrostrictive sensor using data representing a relationship between an observed frequency characteristic of a standard body having at least one known dimension and said dimension of said standard body when a vibration is applied thereto;

wherein said frequency response characteristic is one characteristic selected from the group consisting of a peak height PKx, an area Sx, and a difference between a maximum value and a minimum value of a resonance frequency of one degree, a ratio PKRxy of peak height, a difference PKDxy of peak height an area ratio SRxy, an area difference SDxy, a ratio of the difference between the maximum value and the minimum value, and a difference of the differences between the maximum value and the minimum value between said resonance frequency of one degree and at least one of resonant frequencies of other degrees.