Investigation in the dynamic force equalizationof dissimilar redund ant actuation systemsoperating in active/active mode

With the extensive application of power by wire (PBW) actuators in aircraft industry, a lot of challenges have arisen. One important subject is the force equalization of redundant actuation system composed of dissimilar technologies for position control. In the presented work, the research is focused on one hybrid actuation system combining one servo hydraulic actuator (SHA) and one electro-mechanical actuator (EMA). A virtual test bench is built where the key nonlinear effects are modeled with care. Once the model accuracy is evaluated, the virtual test bench is used for studying the force equalization strategies. The static force equalization has been already presented in a former communication [1], in view of that, the reported research is focused on dynamic force equalization. According to the studied origin of force fighting, three dynamic force equalization strategies are proposed, analyzed, simulated and compared. The first one uses one trajectory generator and two pre-compensators to balance the actuators position loop dynamics; the second one introduces force fighting feedback to compensate the position loop; the third one sets SHA to force control to track the output force of EMA.