Influence of repeated and delayed excitations in combined subspace identification. Issue 12 (2nd December 2017)

• Record Type: Journal Article
• Authors: Erviti, Lara Maria; Giménez, José Germán; Alonso, Asier
• Is Part Of: Vehicle system dynamics. Volume 55:Issue 12(2017:Dec.)
• Page Start: 1884
• Page End: 1908
• Publication Date: 2017-12-02
• Subjects: Modal analysis -- deterministic–stochastic methods -- repeated excitations -- land vehicles -- high speed; Motor vehicles -- Dynamics -- Periodicals; Electronic journals; 629.231
• DOI: 10.1080/00423114.2017.1337208
• Languages: English
• ISSNs: 0042-3114

Abstract

ABSTRACT: The application of combined subspace identification methods to land vehicles would allow the modal parameters of the vehicle to be obtained, while it is in operation, thus improving the vehicle modal characterisation. However, when a land vehicle is circulating through a straight line, the excitations applied to the different axles are identical among them but with a certain time delay. The presence of repeated excitations with different time delays implies that the past and future subspaces include common vectors that may lead to problems in the application of the method. To analyse its influence, an index called the reduction coefficient resulting from excitations (RCE) has been defined. RCE evaluates the amount of information eliminated in the oblique projection due to the effect of repeated excitations. The use of RCE enables the selection of analysis parameters, particularly the sampling frequency, the signals grouping and some specific parameters of the subspace identification methods.