Electro-mechanical diagnostics/prognostics

In support of the Condition Based Maintenance (CBM) philosophy, a theoretical framework and algorithmic methodology for obtaining useful diagnostic and prognostic data from electro-mechanical systems was developed. The methods are based on vibration and modal analyses of the physical components. To illustrate the concept of the derived process, two "real world" models, a PCI circuit card, and an example rotor hub were considered. Models were created using finite element analysis (FEA) techniques, and analyzed to determine fundamental mode shapes and vibration frequencies. Simulations were initially conducted on unadulterated benchmark models, and then faults common to the actual physical components were introduced to the models for subsequent simulation. The results yielded vibration modes characteristic of both undamaged and damaged systems. The obtained system natural frequencies for each FAULT test signal vector were compared to the NORMAL operation benchmark signal. An O(N*logN) correlation technique was utilized for signal discrimination. Application of the developed techniques proved very useful, and correctly identified all inserted FAULTS on the simulated systems.