快速反射镜两轴柔性支承设计

Design of two-axis elastic support for fast steering mirror

提出了基于集中柔度的柔性铰链单元的柔性支承结构,研究了这种柔性支承静动态特性的设计过程和设计方法。首先,从快速反射镜的工作机理出发,分析了系统对柔性支承的特性要求;然后,结合现有两种柔性支承结构的特点,提出基于集中柔度的柔性铰链单元的柔性支承设计;在分析单个柔性铰链刚度特性的基础上,研究了两轴柔性支承的设计方法;最后,以通光口径为Φ90 mm、行程为±2 mrad、工作带宽为300 Hz的两轴快速反射镜为例,进行了两轴柔性支承的设计和特性计算。基于dSPACE半实物仿真系统建立了两轴柔性支承特性实验,对柔性支承的转动刚度进行测试,并对由设计的柔性支承组成的快速反射镜系统的控制性能进行分析。实验结果显示:设计的快速反射镜系统的一阶机械响应频率为78 Hz,闭环控制带宽为340 Hz,满足设计要求,表明基于集中柔度的柔性铰链单元的柔性支承可以满足行程若干mrad,工作带宽数百Hz的两轴快速反射镜的应用需求,且具有加工工艺性好,转动中心稳定等优点。

A new elastic support based on the lumped compliance of flexure hinges was presented for a two-axis Fast Steering Mirror（FSM） system,and the methods to analyze the static and dynamic performance of the elastic support were researched.Firstly,the principle of two-axis FSM and the performance demand of an elastic support were analyzed,and the advantages and disadvantages of several existing elastic supports were researched.Then,a new elastic support based on a right-corner flexure hinge structure was put forward and the static and dynamic performance of the new elastic support was studied in detail.By taking a designed two-axis FSM with the performance in Φ90 mm beam aperture,±2 mrad deflection angle and 300 Hz closed-loop bandwidth for an example,the characteristics of the elastic support were analyzed and the rotational stiffness of the elastic support was measured based on the dSPACE simulation system.Experimental results indicate that the elastic support can meet the performance of FSM well,and its first-order resonance frequency is 78 Hz,and the close-loop bandwidth tested is 340 Hz.It is concluded that the two-axis elastic support based on the lumped compliance of flexure hinge structure can be used for the FSM which needs several mrad deflection angles and several hundred Hz close-loop bandwidths,and it has advanteges in easy machining and a stable rotation center.