基于Stewart平台的有效载荷低阶模态振动抑制

In this study, an active control approach was applied using active and passive payload vibration isolation platforms to suppress the vibration induced by low-order modes of space precision payloads. This system was designed based on the classical two-parameter isolator and the soft Stewart platform. A Skyhook damper was combined with a notch filter control in the vibration isolation system to improve the vibration attenuation capability of the conventional platform. First, the developed laboratory-scale vibration isolation platform for the space payload was developed, and a theoretical rigid-body dynamic model of the payload in the space microgravity environment was established to assess the isolation performance of the apparatus and to design the controllers. Next, the controllers were designed. Finally, the effectiveness of the combined control was verified experimentally. The experimental results showed that in the conventional vibration isolation platform controlled using only the Skyhook damper, the flexible modes of the upper plate near 17.4 and 34.8 Hz were excited easily, which generated resonances near these frequencies in the vibration transmissibility curve of the vibration isolation platform along the vertical direction. The combined control successfully reduced the corresponding amplitudes by approximately 12.2 and 10.19 dB, respectively. The proposed method can be used to enhance the mitigation of disturbances from the spacecraft bus and to significantly reduce the interference near the target flexible modal frequencies, thus achieving high-performance vibration suppression.