Force Equalization for Active/Active Redundant Actuation System Involving Servo-hydraulic and Electro-mechanical Technologies Résumé
On the way to more electric aircraft (MEA), more and more power-by-wire (PBW) actuators are involved in the flight control system. For a hybrid redundant actuation system composed by the conventional hydraulically powered actuators and the PBW actuators, one major issue while they operate on active/active mode is the force fighting between different channels. As the grave influence of force fighting on accelerating material fatigue and increasing power consumption, it must be addressed with attention. This thesis is aiming at proposing some effective force equalization control strategies for a hybrid actuation system involving one servo-hydraulic actuator (SHA) and one electro-mechanical actuator (EMA). For this objective, the position controllers of SHA and EMA are designed on the basis of linear approach and validated on the real test bench of the similar type as a first step. Then, a virtual test bench regarding the realistic behaviors is built in the AMESim simulation environment to accelerate the force equalization strategy design and enable the robustness study through parameters variation. Following this, two static force equalization control strategies are proposed and experimentally validated. The first strategy that introduces integral force fighting signal to compensate the actuator position control is proved a good candidate solution. In the next part, three dynamic force equalization strategies are proposed and assessed on virtual test bench. Their performance sensitivities to parameter uncertainties are studied through the Monte-Carlo method. The first strategy that introduces velocity and acceleration feed-forwards to force the SHA and EMA having similar pursuit dynamics shows a good force equalization performance as well as good segregation and good robustness. In the end, the work presented in thesis is concluded and a perspective is given to the ongoing work.