Green Swashplateless Helicopter Rotor

The present paper describes a novel concept of actively controlled Hiller type servopaddle to achieve rotor primary control. The blades on the swashplateless rotor are coupled to a servopaddle with a piezoelectrically actuated aileron. The aileron commands the paddle pitch which generates a change in the paddle flap angle and blade pitch angle via a mechanical linkage. The system fblade, paddle, ailerong is independent from any other fblade, paddle, ailerong assembly. Therefore, the active servopaddle can create both cyclic and collective inputs. A four degree-of-freedom analysis including aileron dynamics has been developed to predict the dynamic behavior and assess the feasibility of such a swashplateless rotor. The analysis is used to investigate the effect of system parameters on the blade control authority. In addition, hover stand tests preparation is presented. The aim of these tests is to determine the influence of the paddle pitch on the blade pitch, to ensure the whole flight envelope is covered to validate the analysis and finally to assess the present system efficiency with respect to the one of a conventional configuration.