A nonlinear state space approach to tracking damage evolution: experimental application to a gearbox

摘要

A nonlinear observed developed in previous work by the authors (1,2) is used experimentally to track damage evolution in the Mechanical Diagnostics Test Bed (MDTB) at Penn State's Applied Research Laboratory. The observer uses a non-linear. two-time-scale modeling strategy based on the delay coordinate reconstruction of the system's phase space. The method treats "damage" as evolving in a hierarchical dynamical system containing a fast, directly observable subsystem (vibrations) cou-pled to a slow, hidden subsystem (damage). Resoults of tracking damage evolution in the MDTB systems leading to gear-tooth failure are presented. The nonlinear observer tracks changes in the hidden damage stage succeffully. Furthermore, the effective dimensionality of the underlying fast-time system is determined as a by-product of our calculation.