• electromechanical actuator
• motor control
• non linear system
• observer
• optimization
• sensor fusion
• sensors

In pursuing more sustainable aviation transports, the use of Electro-Mechanical Actuators (EMAs) for motion control systems plays a pivotal role, so that a particular attention on reliability enhancement, extreme compactness and weight reduction must be paid in their design.
This work, using as baseline an EMA for secondary flight movables developed by UmbraGroup (Italy), aims at assessing the applicability to primary movables of EMAs equipped with innovative and more compact/lightweight architectures, in which only discrete Hall-sensors are used to measure the motor rotation for the closed-loop position control.
Starting from the definition of the dynamic performance requirements of a primary control surface for large transport aircraft, a cascade PI regulator with three nested control loops on motor current, motor speed and output EMA position is designed. The regulators parameters are identified by using a LTI EMA model and by applying a multi-objective optimization to minimize position tracking deviation, sensitivity to load disturbances and electric power consumption.
Successively, the feasibility in terms of stability and control performances in substituting conventional resolvers with smaller and cheaper discrete Hall sensors is investigated. To compensate for the poor resolution at low speeds, a novel observer-based rotation/speed reconstruction is developed, combining a Luenberger observer with a load disturbance estimator using model-inversion. The reconstruction accuracy is firstly compared with direct interpolation techniques and then extensively analysed in both time and frequency domains, highlight the limitations and potentialities of the proposed solution.