摘要
针对机械式衍射光栅刻划机精密定位工作台定位过程中产生的振动信号特性与光学性能指标(杂散光强度和波前质量)之间的关系,提出利用改进的Hilbert-Huang变换(HHT)获得的时频谱和边际谱对超精密工作台精定位特性进行研究。首先,给出了基于固有模态函数(IMF)筛选和瞬时频率差分求解的HHT信号处理算法。然后,设计了光学测量实验获得工作台50nm定位信号。最后,完成精密定位信号的特征提取和振动测试验证。结果表明:利用改进的HHT可以精确地完成精密定位信号的特征提取,从而为在衍射光栅的制造工艺中从根源上降低衍射光栅的杂散光强度和提高波前质量提供依据。
An improved Hilbert-Huang transformation （HHT） was put forward to reveal the positioning signal characteristic of an ultra-precision worktable by considering the relations between the optical performance index of ：liffraction grating（ stray light intensity and wavefront mass） and the vibration signal generated in the precision positioning process of the worktable of a mechanical diffraction grating ruling engine. Firstly, a HHT algorithm based on intrinsic mode functions＇ selecting criteria and instantaneous frequency＇s difference solution was introduced. Then, an optical measurement test was designed to obtain 50nm positioning response data of a worktable. Finally, the characteristics of the measured ＂signal were extracted and validated with vibration tests. The results indicated that the characteristics of precision positioning signal can be extracted accurately by means of improved HHT, they provide a theoretical reference for reducing Lhe stray light intensity and improving the wavefront mass in process of fabricating gratings essentially.
出处
《振动与冲击》
EI
CSCD
北大核心
2013年第1期89-93,98,共6页
Journal of Vibration and Shock
基金
"十一五"国家科技支撑计划重大项目(2006BAK03A02)
国家重大科研装备研制项目(ZBYZ2008-1)
中国科学院重大科研装备研制项目(YZ200804)
