Health-monitoring of a jamming-tolerant electromechanical actuator with differential ball screws

The paper deals with the theoretical and experimental development of model-based health-monitoring algorithms for a jamming-tolerant electromechanical actuator for flight control applications. A nonlinear dynamic model of the actuator, which includes two motors coupled with differential ball screws in speed-summing arrangement, is experimentally validated with reference to the different operation modes of the system (i.e. with active/active or active/stand-by motors). The validated model is then used to design the health-monitoring algorithms, with a special focus on the characterisation of the failure transient related to the detection, the isolation and the compensation of jamming faults, which imply a control laws switching to engage the appropriate operation mode.