NOISE SOURCE AND TRANSMISSION PATH IDENTIFICATION VIA STATE-SPACE SYSTEM-IDENTIFICATION

Various approaches have been taken to analyze noise/vibration source(s ) end transmission path(s), such as structural analysis, direct measur ement, signal processing, etc. In spite of their remarkable success in understanding noise source(a) and, to a lesser extent, transmission p ath(s), these approaches require further analysis to identify the tran smission paths or contributions from each noise/vibration source. In t he systems and control community, the so-called ''system identificatio n'' has long been used to directly build a mathematical relation (or t ransfer function) between source(s) and response(s), from which the tr ansmission path(s) can be readily inferred. From the various system-id entification techniques, this paper proposes the use of the recently d eveloped state-space system identification, due to its superior perfor mance over existing identification techniques. The first step of ident ification is to define possible candidates for noise/vibration sources and response(s). The independence of the candidate sources is then te sted using state-space system-identification in order to eliminate any redundant source(s) that may degrade the transfer function estimate b etween source(s) and response(s). Once the source independence is guar anteed, the state-space system-identification technique is again appli ed to identify the transmission paths. A scroll compressor is used as a testbed throughout this paper, while the applicability of the propos ed approach is virtually unlimited. Copyright (C) 1997 Elsevier Scienc e Ltd.