Quasi-random pneumatic vibration facility and automatic frequency modulating system therefor
US4181026A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1978 |
| Grant date | Jan 1, 1980 |
| Priority date | — |
| Expiry date | Apr 19, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M7/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A low-cost, multi-axis, quasi-random vibration system includes pneumatically driven vibrators coupled to a resonating, self-attenuating shaker structure to achieve a frequency spectrum and acceleration-level control of a broadband quasi-random vibration output in the frequency range, for example, from 40 Hz to 2 kHz for vibration testing of equipment. The shaker structure consists of flexible interconnected structures whose primary or driving structure acts to mechanically process the vibratory input of the coupled vibrators and whose supporting or driven structure supplies a further vibrational processing to supply the test item with multi-axis multimodal input. Automatic control and pseudo-random modulation of air pressure of the pneumatic vibrators provide closed-loop broadband acceleration-spectrum control and spectrum smearing to enhance frequency content and to prevent the shaker from locking onto any particular vibration frequency, especially a natural frequency of the shaker. Control is achieved in and about three orthogonal axes simultaneously, thus affording a realistic simulation of operational environments. The vibrators' vibration frequency is modulated by means of a v…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.