Robust Optical Interrogators for Electric Propulsion Applications

A new generation of aircraft is being researched at NASA through the Electrified Aircraft Propulsion Technologies (EAPT) project that will use electric motors powered by batteries for propulsion instead of fuel-burning engines. Electrified Aircraft Propulsion (EAP) air vehicles present a challenging environment for measurement and instrumentation systems due to the presence of strong Electromagnetic Interference (EMI) created by the powerful high voltage motors. Fiber optic sensors are an ideal solution to this problem given their light weight, ability to make distributed multi-parameter measurements with a single optical fiber and their native immunity to EMI. However, the associated optical interrogation electronics are not fully immune to EMI and may not operate properly in the presence of these high electric and magnetic fields. This problem demonstrates a need for ruggedized, EMI hardened optical interrogators to support critical testing needs for ground and flight based EAP applications.nbsp;Luna Innovations has partnered with magniX, a leading manufacturer of electric propulsion units (EPUs) for electric-powered aircraft to address this problem by developing and testing an EMI hardened version of its proven Hyperionreg; platform of fiber optic sensor interrogators. The Hyperion is a versatile optical sensing platform, compatible with a variety of sensor types, including fiber-Bragg-grating based temperature and strain sensors that can simultaneously monitor as many as 1,024 sensors at up to 5kHz. The existing commercial product has an optical bandwidth greater than 80 nm and a spectral resolution of 1 pm. The proposed innovation will validate the performance of the modified unit under high levels of EMI exposure through laboratory testing and will demonstrate performance in a relevant operational environment by testing around existing electric propulsion units.