Nokomis proposes a real-time system to perform multi-node abnormality detection and identification in conjunction with wireless sensor development for propulsion system monitoring. The abnormality detection and identification will be achieved by extending Nokomis’ high-sensitivity Hiawatha radio frequency (RF) detection technology.
Typical motor conditions detected with Electromagnetic Interference (EMI) Diagnostics can include stator coil partial discharge, deterioration in slots and on end, winding contamination (dirt, oil, carbon black), bearing problems, misalignment, and shaft oil seal rub. Very low levels of arcing can be detected by high frequency analysis of a wide band antenna signal (and magnetic field probe) using a matched filter model. A single measured variable (RF signal) is sufficient to characterize the degrees of arcing in the DC motor.
During the Phase I period, Nokomis and STTR partner will study and select the motors and actuators best suited to be analogous to propulsion systems of spacecraft. Nokomis will examine, consider and propose optimal locations for placement of near-field or far-field antennas, including antenna size and coaxial cable routing. Vibration and RF signals will be simultaneously recorded during evaluation of the representative propulsion and RF communication environment. The data sets will be analyzed at Nokomis facility for signature identification, isolation, and correlation between vibration signatures and RF signatures at subsequent tasks. Interaction between the Nokomis and STTR partner will verify the temporal and spectral qualities of the signals to create close connections with the underlying physical environments that the sensors aim to characterize.
During the future Phase II period, Nokomis will develop and prototype the wireless sensor that is designed based on Phase I results. The sensor development will be in conjunction with Nokomis’ high-sensitivity Hiawatha RF detection technology.
The proposed real-time RF based propulsion monitoring technology and related sensors are expected to dramatically enhance NASA’s ability for health monitoring on propulsion system with NASA’s traditional fuel and an oxidizer based propulsion systems and the future systems with Leading Edge Asynchronous Propeller Technology (LEAPTech), which is a key element of NASA’s plan to help a significant portion of the aircraft industry transition to electrical propulsion within the next decade.
The future of aircraft propulsion among commercial primes is destined to be electric and electronic. All electric aircraft propulsion systems under development promise significant improvements in energy efficiency, maneuverability, safety, reliability, reduced maintenance costs. The proposed propulsion monitoring technology and sensors will enhance the reliability on such novel propulsion systems.