Multi-Degree-of-Freedom Active Isolation Platform for Microvibrations

Reaction wheels are widely used in the attitude control of spacecraft due to their capability of applying control torques, greatly reducing the propellant requirements and limiting its use to reaction wheel desaturation. However, the presence of unavoidable mechanical imperfections results in significant mechanical disturbances, being applied to the spacecraft, which can severely impact the operation of sensitive payloads. These microvibrations are broadband in nature, and therefore the effective mitigation of their effects requires a high isolation factor throughout a wide frequency range. This paper presents the development and experimental verification of a six-degree-of-freedom active isolation platform for a reaction wheel, integrating a soft suspension and active control using self-sensing actuators. A reduction in the transmitted forces of 65 dB at 270 Hz was experimentally demonstrated, while exhibiting negligible amplifications by its suspension resonance, which constitute very attractive performances.