基于音圈作动器的大型柔性结构振动主动控制

Active Vibration Control for a Large Annular Flexible Structure Based on Voice Coil Actuators

大型环形柔性结构作为卫星天线的典型结构,由于其显著增大的天线口径有效提高了通信精确度,而使重量仅微小增加,已经成为大口径卫星天线的主流结构。同时它具有固有频率极低、阻尼弱、刚度小等缺点,低频、长时间的模态响应很容易被激起。因此,大型环形柔性结构的振动控制变得尤为重要。针对大型环形柔性结构振动问题,提出一种基于激光位移传感器、音圈作动器和PD-fuzzy控制算法的振动主动控制方法。其中,激光位移传感器能够测量的最小位移为0.01 mm,音圈作动器输出位移和力,基于激光位移传感器的反馈信号运用PD-fuzzy控制算法控制音圈作动器。建立大型环形柔性结构的有限元模型并分析其特性,同时构建试验验证系统。结果表明,该振动主动控制方法性能良好,能够控制大型环形柔性结构的超低频振动,而不会产生附加刚度。

Large annular flexible structures(LAFS)are typical antenna structures for satellites.Since these structurescan significantly enlarge antenna’s aperture and effectively improve the communication accuracy with minimum additivemass,they have become the mainstream of large aperture antenna structures.However,they have some disadvantages,suchas low natural frequencies,low damping ratio and low stiffness so that they always suffer from low frequency and longtimemodal responses.Therefore,the vibration control of LAFS is very important.This study proposes a novel active vibrationcontrol method based on a laser displacement sensor unit,a voice coil actuator and a PD-fuzzy control algorithm.Themeasurable minimum displacement of the laser displacement sensor unit can reach0.01mm.The voice coil actuatorgenerates the displacement and driving force.Based on the feedback signal from the laser displacement sensor unit,the PDfuzzycontrol algorithm is used to control the voice coil actuator.A FEM model of the LAFS is established,and itscharacteristics are analyzed.Meanwhile,an experimental system is set up.The results demonstrate that the novel activevibration control method has a good performance.This active vibration control method can control vibration at ultralowfrequencies without additional stiffness.