Embedded Health Monitoring for Propulsion Control System Actuators

Latent degradation of propulsion actuators adversely impacts the stability and dynamic performance of the aircraft control system. Sentient’s Phase I effort successfully demonstrated the feasibility of monitoring actuator degradation using robust and computationally inexpensive hybrid model/feature based methods. The goals of Phase II are to expand upon and validate the physics-based actuator model and fault estimation routines, and then apply them to the joint strike fighter (JSF) converging nozzle actuation system (CNAS). To achieve these objectives, the model will be further developed to include additional effects. Then, the nominal and faulted models will be validated using data from Sentient’s hydraulic actuator test rig. Next, the diagnostic algorithms will be demonstrated on the test rig with seeded faults and a simulated pre-flight test sequence. The algorithms will also be validated against healthy and faulted test stand data for the actual JSF CNAS in collaboration with Pratt & Whitney. Finally, by collaborating with the controller OEM, Sentient’s validated actuator fault estimation system will be designed for integration into the JSF control system. The diagnostics will be demonstrated to a technology readiness level of 6 by the conclusion of Phase II.