PROCESSING OF SIMULTANEOUS MECHANICAL RANDOM RESPONSE SIGNALS: INTEGRATION, DIFFERENTIATION AND PHASE SHIFTS CORRECTION
✍ Scribed by A.L. Audenino; G. Belingardi
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 450 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0888-3270
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✦ Synopsis
Several experimental system identification methods require simultaneous sampling of mechanical quantities. The paper discusses problems connected with the use of multisensor set-ups and problems arising when integration or differentiation processes are employed to obtain unmeasured time histories and reduce the number of sensors.
Three orders of problems related to integration or differentiation procedures must be taken into account: intrinsic problems, numerical algorithm problems and computer round off problems. Experimental and numerical details to obtain reliable data are given in the paper. The estimated data are compared with the exact experimental data using two different experimental set-ups.
To avoid phase shift among measured time histories and to obtain real-time acquisition, no filtering of transducer output signals was carried out; in spite of this, phase shifts among measured time histories have been detected. A complete analysis of the frequency response of the transducers showed constant phase delays between different channels; consequently the data have been time shifted in order to obtain phase coherence.