  We use the methodology of singular spectrum analysis (SSA), principal
component analysis (PCA), and multi-fractal detrended fluctuation analysis
(MFDFA), for investigating characteristics of vibration time series data from a
friction brake. SSA and PCA are used to study the long time-scale
characteristics of the time series. MFDFA is applied for investigating all time
scales up to the smallest recorded one. It turns out that the majority of the
long time-scale dynamics, that is presumably dominated by the structural
dynamics of the brake system, is dominated by very few active dimensions only
and can well be understood in terms of low dimensional chaotic attractors. The
multi-fractal analysis shows that the fast dynamical processes originating in
the friction interface are in turn truly multi-scale in nature.
