The directional Wigner distribution and its applications

Abstract

A new signal processing technique, the directional Wigner distribution (dWD), is presented to characterize the instantaneous planar motion of a measurement point in a structure from its transient complex-valued vibration signal. It is proven that the auto-dWD essentially tracks the shape and directivity of the instantaneous planar motion, whereas the phase of the cross-dWD indicates its inclination angle. Finally, the technique is successfully applied to two practical cases: a rotor during run-up and an automobile engine during crank-on/idling/engine-off. (C) 1998 Academic Press.