Abstract: Compared with numerous helicopter vibration reduction technologies, the top-mounted active control technology on the rotor hub demonstrates significant advantages in volume, weight, and vibration suppression efficiency. Domestic research in this field remains in its early stages. A top-mounted active actuation system on the rotor hub was specifically designed to meet the actual operational requirements of a certain aircraft model. First, vibration reduction demands were determined in the rotating coordinate system. A mathematical model of the actuation unit output force was established, deriving the functional relationship between output force and motor control. An actuator configuration with automatic mass balancing functionality was designed. Second, to address the contradiction between the system’s dynamic response rapidity and the voltage-current characteristics of the DC bus, an optimal position trajectory control strategy was proposed. The single-motor speed reference profile was planned as a quadratic function to reduce the inner-loop tracking difficulty. Leveraging the electrical braking energy flow characteristics, dual-motor position reference profiles were optimized to achieve internal energy recovery and reduce voltage-current surges on the DC bus. Finally, an engineering prototype was developed. Normalized experimental data show that the output force amplitude during actuation unit power loss is 0.11 (per-unit value), with a maximum dynamic response time of 0.94. After implementing the dual-motor position optimization strategy, current surges decreased from 12.5 A to 8.3 A. These results verify the feasibility and effectiveness of the system, providing practical guidance for the actual aircraft application of hub-mounted active actuation systems in China.

Key words: top-mounted active control on rotor hub, top-mounted active actuator for rotor hub, position trajectory, dynamic response, power supply characteristics