Prognostic-enabling of an electrohydrostatic actuator (EHA) system

Abstract

A proof-of-concept prognostic solution for certain failure modes in the power electronics that drive the flight-critical F-35 Joint Strike Fighter (JSF) electrohydrostatic actuators (EHA) is presented. This program was led by Ridgetop Group under U.S. NAVAIR Small Business Innovation Research (SBIR) funding, and included Lockheed Martin Aeronautics Company (LM), Moog, and Dell Services (Netherlands). Degradation of the optocoupler that isolates the control electronics from the power electronics was simulated in the lab by physically changing resistance values to alter the current transfer ratio. It is proposed that this degradation would also be indicative of insulated gate bipolar transistor (IGBT) wearout. The experimental approach, the test facility, the data analysis and the findings are discussed. An Off-Board Prognostics Health Management (OBPHM) Demonstrator, developed by Ridgetop Group and Dell Systems and representative of the production OBPHM application currently deployed for the F-35 is described. Implementation considerations and challenges are also discussed.