冲击扰动下空间柔性体振动的主动抑制研究

Research on Active Vibration Suppression of Spatial Flexible Body under Impact Disturbance

将浮动基Stewart平台作为振动控制作动装置,串联在卫星平台与空间大柔性体之间,并设计积分加速度反馈和积分力反馈控制器来抑制柔性体振动。对比分析采用被动阻尼、积分加速度反馈、积分力反馈振动抑制方法时柔性体与卫星本体之间的位移传递特性。通过计算系统各阶模态下Stewart平台的模态应变能比例,明确Stewart对柔性体低阶模态振动抑制效果好于对高阶模态振动抑制效果,并分析不同控制策略下系统稳定性,给出最佳振动控制增益。建立“卫星本体-Stewart平台-柔性太阳阵”的Adams模型,研究太阳阵受瞬态激励和姿态机动工况下,分别采用积分加速度反馈和积分力反馈时Stewart平台的振动抑制能力。结果表明,将Stewart平台作为主动作动装置,对于冲击扰动引起的低频柔性振动具有显著抑制作用,且积分力反馈的振动抑制效果优于积分加速度反馈。

The floating-based Stewart platform installed in the series between the satellite platform and the large space flexible body is used as the actuator for vibration control.In order to suppress the vibration of the flexible body,the integral acceleration feedback and integral force feedback controllers are designed.The characteristics of displacement transfer between the flexible body and the satellite body are compared and analyzed using passive damping,integral acceleration feedback and integral force feedback vibration suppression methods.By calculating the modal strain energy proportions of Stewart platform under different order modes of the system,it is clear that Stewart platform has better suppression effect on low mode vibration of flexible body than that on high mode vibration.The stability of the system under different control strategies is proved and the optimal vibration control gain is deduced.The model of"satellite body-Stewart platform-flexible Solar array"is established in Adams,and the vibration suppression ability of Stewart platform under the transient excitation and attitude maneuvering conditions is studied using integral acceleration feedback and integral force feedback respectively.The results show that the Stewart platform as the active actuator can suppress the low frequency flexible vibration caused by impact disturbance significantly,and the vibration suppression effect of integral force feedback is better than that of integral acceleration feedback.