Natural Pitch Stabilization of Bicopters in Hover Using Lift-Propeller Gyroscopics

作者：Gress G R^*

来源：Journal of Guidance, Control, and Dynamics, 2018, 41(2): 476-487.

DOI：10.2514/1.G002468

The ability of a hovering bicopter to be self-or passively stabilized in pitch without the use of active electronic devices is investigated using the aircraft equations of motion. The bicopter's dual, noncyclic, and laterally displaced lift propellers are allowed to precess freely in oblique directions as gyroscopes. From the resulting characteristic equation representing state-space natural frequencies, it is found that the aircraft can, in theory, be stabilized in pitch by moderating the propeller pod tilting with viscous dampers. However, in practice, centering springs are also required, and their use destabilizes pitch attitude but maintains stability of the aircraft pitch rate. It is determined that full stability can be restored with the addition of a pilot, here represented as a simple integral controller. It is also found that the springs and dampers allow a pilot to intentionally direct longitudinal motion of the aircraft via a servo while maintaining stability. The result is an aircraft whose gyroscopic propellers naturally provide stabilization and high-speed responses to external disturbances on their own, and whose pilot and servo perform the slower fine-tuning and flight-path control duties. This separation can reduce structural stresses, control-servo loads, and energy consumption.

• 出版日期2018-2