Abstract
With the development of power-by-wire technology for more electric aircraft, the electro-mechanical actuator (EMA) has the advantages to replace the conventional hydraulic servo actuator in some aerospace flight controls. Conventional hydraulically powered trimmable horizontal stabilizer actuation (THSA) system is nowadays developed to be electrically supplied. Given their safety-criticality, no-back mechanism and redundant load paths are utilized to meet the flight control requirements. However, rare literatures have introduced these functions and addressed the virtual prototyping activities from system-level point of view. This paper proposed such a model of a THSA system with dual electric power sources and fault-tolerant mechanical load paths. The nonlinear effects of components are considered with realism, and system-level simulation test is conducted to support the model-based system engineering (MBSE) approach. The models are developed with a power view instead of a pure signal view. Focusing on the friction effect and compliance effect with backlash or preload, some improved and novel approaches are adopted for these crucial components and validated via experimental results. Meanwhile, the implemented system-level model enables injection of crucial faults. Finally, the simulation of the proposed model shows that it is an efficient resource to investigate the actuator’s dynamic performance, to virtually prove that the actuator meets the fail/safe constraint, and to demonstrate the soundness of the fault monitoring functions.
