Health Monitoring Methodologies for Aerospace Electromechanical Actuation Systems

Electrical actuation concept fits within the worldwide strategy of more electric aircraft. However, the integration of linear electromechanical actuators is challenging in safety critical systems due to jamming of the driven load. That fault is critical in many applications such as primary flight controls or landing gears extension and steering. This paper reviews solutions currently available for aerospace application, limits for their effective deployment and possible solutions to achieve a condition-based maintenance to reduce costs still guaranteeing safety. Typical conversion mechanisms adopted so far are described along with the failure modes of these systems, contrasting their many advantages. Particular attention is given to the jamming and possible strategies to avoid it. In particular, any structural alteration which can induce jamming can be monitored as prescribed by predictive maintenance approach in order to detect upcoming faults in advance. Among different possibilities available to timely assess latent fault inducing jamming, the analysis of electrical current and/or mechanical vibrations signals by deterministic or statistic approaches are the most promising. In addition they show strong potentialities in implementing data fusion and learning algorithms to identify different EMA operational conditions.