Force fight compensation for redundant electro-mechanical flight control actuators

Electro-mechanical actuators (EMAs) for large civil aircraft require a nominal operation in active/active mode for certain primary flight control surfaces, like aileron and rudder, and thus measures to guarantee synchronous actuator movements. An approach for effective force fight compensation is introduced. It comprises a feedback Loop designed as an optimal linear quadratic output regulator (LQR) and a feedforward controller based on a General regression neural network (GRNN). The implemented control scheme was validated on a test rig matching the physical properties of an aileron of a commercial single aisle aircraft