A Vibrational Analysis of the Fecker Inertial Test Table,
Abstract
The Inertial Guidance Research Division of the Frank J. Seiler Research Laboratory at the USAF Academy employs a Fecker Inertial Test Table for use in inertial instrument testing. The test table is mounted on a seismic isolation pad (iso-pad) to provide a motionless test environment. Sensors on the iso-pad detect seismic activity of the pad and provide motion correction signals to actuators through a feedback system. The actuators keep the iso-pad free of motion due to external disturbances. The iso-pad motion correction system rolls off above 20 Hz to avoid actuating the pad at or near its natural resonant frequencies of 59, 65, and 67 Hz, thus avoiding instabilities. A DC-20 Hz motion-correction frequency band is also adequate for the inertial instrument tests conducted by the Inertial Guidance Research Laboratory. The Inertial Test Table is investigated for natural resonant frequencies within the 20-50 Hz range. A strong resonant peak occurs at 22 Hz in both the vertical and horizontal modes. The rotational resonant peak occurs at 34 Hz. Extensive alterations to the test table structure caused no changes in amplitude or frequency of the resonances.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1977
- Accession Number
- ADA044826
Entities
People
- G. Douglas Evans
Organizations
- Air Force Research Laboratory