High force vibration testing with wide frequency range
View Patent ↗A shaker assembly for vibration testing includes first and second shakers, where the first shaker includes a piezo-electric material for generating vibration. A support structure permits a test object to be supported for vibration of the test object by both shakers. An input permits an external vibration controller to control vibration of the shakers.
1. An apparatus for vibration testing, comprising:
a shaker assembly including first and second shakers, said shaker assembly configured to support a test object thereon for vibration of the test object by both of said shakers, said first shaker including a piezo-electric material for generating vibration, and said second shaker rigidly fastened to said first shaker and configured to generate vibration without using piezo-electric material; and
a control system coupled to said shakers for controlling vibration of the test object.
2. The apparatus of claim 1 , wherein said first shaker is mounted on said second shaker and is configured to mount the test object thereon to permit said second shaker to vibrate said first shaker and the test object.
3. The apparatus of claim 2 , wherein said control system includes a first input configured to receive a first feedback signal indicative of vibration of said first shaker.
4. The apparatus of claim 3 , wherein said control system includes first and second SISO controllers coupled to said first input and responsive to said first feedback signal for respectively controlling vibration of said first and second shakers.
5. The apparatus of claim 3 , wherein said control system includes a MIMO controller coupled to said first input and responsive to said first feedback signal for controlling vibration of said first and second shakers.
6. The apparatus of claim 3 , wherein said control system includes a second input configured to receive a second feedback signal indicative of vibration of said second shaker.
7. The apparatus of claim 6 , wherein said control system includes first and second SISO controllers respectively coupled to said first and second inputs and respectively responsive to said first and second feedback signals for respectively controlling vibration of said first and second shakers.
8. The apparatus of claim 2 , wherein said second shaker is configured to produce vibration relative to a plurality of vibration axes.
9. The apparatus of claim 1 , wherein said second shaker is one of a hydraulic shaker and an electro dynamic shaker.
10. The apparatus of claim 1 , wherein said first and second shakers are respectively configured to vibrate the test object in first and second vibration frequency ranges, and wherein said first range is higher and wider than said second range.
11. The apparatus of claim 10 , wherein said first and second ranges are substantially non-overlapping.
12. A shaker assembly for vibration testing, comprising:
a first shaker, including a piezo-electric material for generating vibration;
a second shaker rigidly fastened to said first shaker and configured to generate vibration without using piezo-electric material;
a support structure configured to permit a test object to be supported for vibration of the test object by both of said shakers; and
an input for permitting an external vibration controller to control vibration of said shakers.
13. The shaker assembly of claim 12 , wherein said support structure includes said first shaker mounted on said second shaker and said first shaker configured to mount the test object thereon to permit said second shaker to vibrate said first shaker and the test object.
14. The shaker assembly of claim 13 , including a first sensor positioned to sense vibration of said first shaker and configured to provide to the external vibration controller a first feedback signal indicative of said vibration of said first shaker.
15. The shaker assembly of claim 14 , including a second sensor positioned to sense vibration of said second shaker and configured to provide to the external controller a second feedback signal indicative of said vibration of said second shaker.
16. The shaker assembly of claim 13 , wherein said second shaker is configured to produce vibration relative to a plurality of vibration axes.
17. The shaker assembly of claim 12 , wherein said input provides first and second control signals respectively to said first and second shakers.
18. The shaker assembly of claim 12 , wherein said second shaker is one of a hydraulic shaker and an electro dynamic shaker.
19. The shaker assembly of claim 12 , wherein said first and second shakers are respectively configured to vibrate the test object in first and second vibration frequency ranges, and wherein said first range is higher and wider than said second range.
20. The shaker assembly of claim 19 , wherein said first and second ranges overlap one another.