SYSTEM AND METHOD FOR DIAGNOSING AND CONTROLLING ELECTRIC MACHINES

A system and method of diagnosing and controlling electric machines such as engines is provided. The presence of an instability in a physical characteristic of the device is diagnosed by providing a digital input signal representative of the physical characteristic to a computer system. A wavelet transform is performed on the digital input signal to provide a set of wavelet coefficients, and at least a first probabilistic measure is determined with respect to the coefficients. Preferably, more than one probabilistic measure of the wavelet coefficients are determined and used to identify the precursor. The probabilistic measures may be dispersion or other measures provided by a high rank correlation matrix. The probabilistic measure(s), and possibly other supplemental device related information, are analyzed to identify a precursor associated with the instability. By identifying the precursor prior to the development of a malfunction in the device, a command execution unit may be used to control the device, in accordance with an instability control approach, to avert the development of a malfunction. The system and method may be applied to devices in real time under time varying, as well as stable or unstable, operating conditions.