Adaptive decoupling synchronous control of dissimilar redundant actuation system for large civil aircraft

In order to meet the increasing reliability requirements of actuation system for large civil aircraft, the novel distributed dissimilar redundant actuation system composed of one hydraulic actuator (HA) and one electro-hydrostatic actuator (EHA) has been applied to the design of advanced aircraft. This configuration can greatly improve the system reliability and effectively avoid potential common-mode/common-cause (CM/CC) failure. However, this actuation configuration can exhibit force fighting problem between HA and EHA due to their different driving mechanisms and rigid coupling when they operate in the active/active mode, which may even cause damage to the control surface. To resolve this problem, an adaptive decoupling synchronous controller (ADSC) is proposed in this study. The coupling effect between HA and EHA is taken into account, and an adaptive decoupling controller is designed to eliminate the coupling term. Parameter adaption law is designed for the parametric uncertainties. In addition, a feed-forward compensator is proposed to compensate for the difference between HA and EHA by accelerating the dynamic response of EHA. Finally, the comparative simulation results indicate that the proposed ADSC controller has high speed/high robustness performances and can effectively reduce the force fighting between HA and EHA.