A Prognostics Approach for Electronic Damage Propagation and Analysis in Electromechanical Actuator Systems

As the aviation industry evolves toward next-generation fly-by-wire vehicles, hydraulic actuators are being replaced with their electro-mechanical actuator (EMA) counterparts. By eliminating fluid leakage problems while reducing weight and enhancing vehicle control, the feasibility of EMAs in avionic applications has been established. However, due to the inherent nature of electronic components and systems to degrade and eventually fail, improved diagnostic and prognostic methods are required to maintain the all-electric aircraft at safe levels. In this paper, an innovative approach to the emulation of avionic EMA operation is presented. A state-of-the-art testbed, which integrates a fault-enabled 12 VDC Switch Mode Power System (SMPS) with a faultenabled servo drive H-bridge circuit, will be presented. Realistic load profiles can be applied to this scaled-down EMA testbed while executing the in-flight actuator motion commands in real-time. To examine and mitigate the effects, the EMA hybrid emulator is designed to support fault insertion of degraded electronic components, such as the power transistors of the motor drive, to analyze the servo loop response of an aged actuator system. The EMA motion trajectory, or position, data is acquired with various degradation levels of power electronics components in order to populate a fault-to-failure progression (FFP) database of actuator servo loop response signatures. Ultimately, the FFP signature database is leveraged to develop prognostic methods to assess the State of Health (SoH), estimate Remaining Useful Life (RUL), and support Condition-Based Maintenance (CBM) of avionic EMA systems.