两路反馈外腔自混合干涉信号的相位提取方法

在分析两路反馈外腔结构自混合干涉(SMI)模型的基础上,对两路自混合干涉信号的处理方法进行了理论分析和仿真验证。在弱反馈水平下,利用希尔伯特变换原理实现了两路合成信号相位的重构,并对合成信号相位分解得到了两路外腔反射体位移的波形,最大误差小于1.5rad。在对含噪的两路自混合干涉信号进行预处理时,采用小波软阈值和集合经验模态分解(EEMD)相结合的算法,达到了良好的去噪效果。

两路微振动信号的光纤F-P腔干涉测量

法布里-珀罗(F-P)腔传感器结构简单,复用能力强,对导致其腔长发生变化的物理量灵敏度高,在超精密测量领域日益受到重视。为了使用一套光纤F-P腔测量两个目标,设计了两路反馈信号光纤F-P腔干涉系统,同时开展两路微振动信号测量。对两路微振动反馈F-P腔干涉信号,经多次取包络分解,得到了高、低频信号频谱,进而计算出待测目标振幅。实验结果表明,通过低频信号恢复待测目标振幅的误差为1.32%,通过高频信号恢复待测目标振幅的误差为6.63%。该方法有效实现了两路反馈光纤F-P腔干涉信号的分离,拓展了测量通道,提高了抗干扰能力。

CLOSE-LOOP DESIGN OF PULSE POWER SUPPLY FOR ELECTRICAL DISCHARGE MACHINING

The dynamic performance and the stability are essential for a system. A new circuit topology used for electrical discharge machining (EDM) power and made up of complex-pulse (voltage-pulse and current-pulse) is presented. The large-signal model of it is also derived. Based on the comprehensive analysis of the system model, the compensator is designed to make the system match better and to improve its dynamic performance and the stability under perturbations. Finally, the design methods and the analysis are verified by simulation and experimental results.