Investigations into an Active Vibration Isolation System for Helicopters with Rigid and Elastic Airframe Modeling

摘要

A system for active rotor isolation was investigated to compensate for blade number harmonic excitation of the rotor and limit the static relative movement of the rotor drive unit. Several sensor configurations were studied for the first completed regulator design of a single rigid function model with a modified Riccati design. This single axis computer model was reviewed and extended for the elastic helicopter airframe modeling (by means of a modified Riccati design). Computer results show that the active rotor isolation is superior in design to all known passive rotor isolation systems. The regulators designed for the single axis computer model show very good isolation of vibration at the 4- and 8- fold rotation frequencies of the rotor, in conjunction with rapid swinging. In addition, the separation between the rotor drive unit and the airframe was reduced with an additional load factor.