Hybrid Active Vibration Control of Helicopter Fuselage Driven by Piezoelectric Stack Actuators

The vibration loads of a helicopter rotor are transmitted to the fuselage through gearbox support struts and cause severe vibration of the fuselage. A piezoelectric stack actuator has the advantages of light weight, a large driving force, small driving displacement, a wide working frequency range, and a fast response speed; it is an ideal actuator for the active vibration control of structures. The piezoelectric stack actuators are installed on the gearbox support struts, which can effectively control the vibration of the helicopter fuselage. In this paper, the dynamic models of the piezoelectric stack actuators, the rotor/gearbox, the gearbox support struts, and the fuselage coupling system are established. Combining the adaptive harmonic synchronization identification and updating algorithm with the sliding-mode algorithm, the adaptive harmonic feedforward/sliding-mode feedback hybrid active control method for helicopter fuselage vibration is proposed. The simulation results show that, under the excitation of the rotor vibration loads with the first three rotor passing frequencies, the acceleration responses of the fuselage in three directions by using the proposed hybrid active control method are reduced by more than 98%; when the amplitudes, phases, and frequencies of the vibration loads are changed, the active control of the fuselage vibration by using the hybrid active control method has a fast convergence speed and a strong adaptive ability.