A Piloted Simulator Investigation of Decoupling Helicopters by Using a Model Following Control System

A U.S. and German piloted simulation experiment conducted to evaluate the performance of a model following control system by applying it to hingeless-rotor and teetering-rotor helicopters is reported. The explicit model was a linear, decoupled model such that the pilot commanded pitch attitude with the longitudinal cyclic, roll attitude with the lateral cyclic, yaw rate with the pedals, and Earth-fixed downward velocity with the collective. The results of the simulation indicate that the performance of the model following control system is primarily dependent on the limitations of the actuating system. Satisfactory handling qualities were achieved for both augmented helicopters flying two specified evaluation tasks: dolphin and slalom maneuvers. The significant improvements in task performance and handling qualities achieved for these two radically different helicopters, augmented with the designed model following control system, indicates the flexibility and versatility of this control technique.