Static force equalization for dissimilar redundant actuator system

The dissimilar redundant actuator system (DRAS) which consists of power-by-wire actuators, EHA (electro-hydrostatic actuator) and EMA (electro-mechanical actuator), addresses the problem of the distribution of central hydraulic source and pipelines. It also resolves the common fault, which indicates the trend of more-electric-aircraft. To start with, the construction as well as the working principle of the DRAS was described. Considering the air load of control surface and connection stiffness, the closed-loop system model within active/active working mode was built up. Further, the mechanism of static force fighting was introduced. The idea which uses the method of adjusting the electrical parameters so as to compensate the static force fighting was proposed, and based on the above principle three kinds of static force equalization for eliminating static force fighting were put forward, and then theoretical and simulation analysis were discussed. Finally, a comprehensive comparative analysis on the elimination of static force fighting, isolation and other aspects was exhibited for the three control strategies. The results provide theoretical directions for DRAS design and static force fighting solutions.