Robust Optical Interrogators for Electric Propulsion Applications

Luna Innovations has partnered with magniX, a leading manufacturer of electric propulsion units (EPUs) for electric-powered aircraft, to develop and test an EMI hardened version of its proven Hyperion fiber optic sensing platform to support critical testing needs for ground and flight based Electrified Aircraft Propulsion (EAP) applications. The Hyperion is a versatile instrument, compatible with a variety of fiber optic sensor types, including temperature, strain, pressure, and acceleration sensors based on Fiber Bragg Grating and Fabry-Perot technologies. The Hyperion can simultaneously monitor as many as 1,024 sensors at data rates up to 5kHz. During Phase I Luna tested the Hyperion at magniX on a 650kW electric aircraft motor driving a propeller and characterized the EMI environment during the test. In addition, the Hyperion was exposed to high levels of EMI through formal testing at an EMC laboratory. The Hyperion performed within specifications during all of the test campaigns proving initial viability for EAP applications. A detailed plan for creating a robust EMI and flight hardened unit was developed incorporating standard DO-160G requirements. The proposed Phase II will result in the development of a ruggedized, flight capable Hyperion interrogator that can withstand the high EMI and demanding physical operational environment of emerging electric aircraft applications. This system, coupled with distributed fiber optic strain and temperature sensors, will establish the commercial viability of the platform. During the Phase II effort, Luna will work with its partners to build a prototype system, test it at extremes of temperature, vibration and EMI exposure, and demonstrate its successful operation in relevant EAP test scenarios. magniX will provide facilities, equipment and test opportunities to enable the evaluation of the system, culminating in a final technical demonstration of the rugged Hyperion in an operational environment. A new generation of aircraft propelled by electric motors is being developed at NASA, including the X-57 Maxwell. Electrified Aircraft Propulsion (EAP) vehicles present a challenging environment for 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 measurements 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 fields. This problem demonstrates a need for ruggedized, EMI hardened optical interrogators to support critical testing needs for ground and flight based EAP applications. 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, flight-capable version of its proven Hyperion® platform of fiber optic sensor interrogators. The proposed effort will result in the development of a ruggedized, flight capable Hyperion interrogator that can withstand the high EMI and demanding operational environment of emerging electric aircraft applications. This system, coupled with distributed fiber optic strain and temperature sensors, will establish the commercial viability of the platform. During the Phase II effort, Luna will build a prototype system, test it at extremes of temperature, vibration and EMI exposure, and demonstrate its successful operation in relevant EAP test scenarios. magniX will provide facilities, equipment and test opportunities to enable the evaluation of the system, culminating in a final technical demonstration of the rugged Hyperion in an operational environment. The following technical objectives and work plan were formulated: 1. Extreme limit testing of the Hyperion product 2. Design and construction of a ruggedized flight capable Hyperion 3. Demonstration of performance in demanding test conditions 4. A mature commercialization strategy Task 1: Project kickoff and work plan review Task 2: Extreme limit testing for EMI exposure Task 3: Limit testing at flight environmental conditions Task 4: Field testing and EMI measurement Task 5: Ruggedized flight unit design and fabrication Task 6: Ruggedized unit testing Task 7: Capstone demonstration test Task 8: Commercialization and reporting
Benefits: The proposed research will directly address NASA’s need for an optical interrogator that is immune to EMI. This system will find potential applications in electric powered aircraft such as the X-57 Maxwell, SUSAN, STARC-ABL, N3-X and other vehicles being developed under the Revolutionary Vertical Lift Technology (RVLT) and Electrified Aircraft Propulsion Technologies (EAPT) projects. It may also be useful for ground testing at the NASA Electric Aircraft Testbed (NEAT) or for other applications under the AATT or EPFD programs. Electric powered aircraft are poised to become commonplace in the coming years given the decreased cost of operation and lower environmental impact of electrified aircraft propulsion technologies. The proposed EMI-hardened Hyperion will find a ready market for instrumentation in commercial EAP applications due to the challenges presented by conventional wired electronic systems.