傅里叶光谱仪平动式光程扫描控制系统设计

为实现大气痕量气体的临边和天底超光谱探测，利用时间调制型傅里叶变换光谱仪获取光谱信息，其干涉仪控制系统中光程扫描速度稳定度≥99.5%。针对光程扫描行程长，扫描速度稳定性要求高，设计平动式光程扫描的干涉仪控制系统，并给出扫描实现原理图。由于控制系统存在摩擦力、振动等干扰导致扫描速度波动，理论分析其对干涉信号强度和反演光谱的影响。鉴于角镜扫描运动和扰动具有周期性特点，提出插入式重复控制器来抑制周期性干扰，改善动镜运动速度的匀速性。对控制策略进行MATLAB数值仿真和实验验证，实验结果表明:当角镜以10.625 mm/s运动时，插入式重复控制器可逐周期地改善角镜运动稳定度，最终位移误差为±0.000 25 mm，速度误差为±0.000 4 mm/s；满足速度稳定度≥99.5%的要求。

Design of translating optical path scanning control system for Fourier spectrometer

To achieve the ultra-spectral detection of atmospheric trace gases in both nadir and limb, the time-modulated Fourier transform spectrometer was used to obtain the spectral information, and the optical path scanning speed stability satisfied greater or equal to 99.5%. In this paper, a control system of the translational scanning interferometer was investigated and the system principle diagram was presented. Considering the long-range optical path distance (OPD) and high scanning speed stability requirements, a interferometer control system of the translational optical path scanning was applied, and the schematic diagram of the scanning implementation was given. As the fluctuation of scanning speed caused by frictions, mechanical vibrations and other disturbances, its influence on the interference signal intensity and inversion spectrum was theoretically analyzed. The motion of OPD scanning and the interference have a characteristic of periodicity, this paper proposed a plug-in repetitive controller, which has an excellent in suppressing periodic disturbances, and implements uniform scanning. MATLAB numerical simulation and experimental verification were carried out for the control strategy, the results indicate that the plugin repetitive controller can improve the speed stability periodically. When the angular mirror moves at 10.625 mm/s, the final displacement error is about ±0.000 25 mm, and the velocity error is about ±0.000 4 mm/s, which meet the performance requirements.