ANALYSIS OF A SWASHPLATELESS HELICOPTER ROTOR WITH ACTIVE SERVOPADDLES

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 ap angle and blade pitch angle via a mechanical linkage. The system {blade, paddle, aileron} is independent from any other {blade, paddle, aileron} 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 elect of system parameters on the blade control authority.