Helicopter Vibration Reduction Simulation using Closed-loop Higher Harmonic Control Technique Considering Actuator Amplitude Limitation

A numerical simulation that considers the actuator amplitude limitation on the higher harmonic control (HHC) system was performed to reduce helicopter vibration. To this end, a technique was applied to limit the amplitude of the control input while maintaining its phase. A method was applied to adjust the actuator amplitude after calculating the open-loop optimal control input. An amplitude-limited closed-loop control algorithm examined and adjusted the amplitude of the control input signal after control input update. A comparative analysis was conducted on the changes in vibration control performance and vibratory load acting on the pitch link structure connected to the HHC system, considering the actuator amplitude limitation.