Progress in turbomachinery prognostics and health management via eddy-current sensing

This paper describes recent progress in an ongoing program of prognostics and health management for jet engines and other turbomachinery. The primary enabling technology is an eddy-current sensor: a magnetic sensor relying for its operation on high-frequency eddy currents actively induced in passing blades. We summarize the sensor principles, review improvements in sensor system technology over the past year, illustrate the performance of the sensor system and associated algorithms with results from recent field tests, and briefly describe the PHM program in which the sensor system plays a key role.