Smart spring control of vibration on helicopter rotor blades
A study was conducted to demonstrate the use Smart Springs to control the helicopter airframe vibration. It involved modeling the Smart Spring as a replacement for the conventional rotor pitch link and an advanced aeroelastic/aeroacoustic simulation tool for actively controlled rotors. The Smart Spring was implemented as a subloop of the main aeroelastic calculations in SMARTROTOR, which provided the boundary condition for the pitch degree of freedom of the structural module. The parameters of Smart Springs were adjusted to achieve the control strategy at the frequency of 4/rev. Numerical simulation results showed that the Smart Spring can be used as a structural control device to attenuate helicopter rotor higher-harmonic loads transmitted to the fuselage through the pitch link. The rotor trim and 'collective and cyclic control commands' were remained unaffected by Smart Spring.