| Fourier transform spectrometer is an important infrared remote sensing instrument, whichis applied to obtain high sensitivity, high spectral resolution and multi-channel atmosphericradiation spectra, and by which vertical distributions of temperature and humidity of atmospherecan be inversed. High precision control of moving mirror is one of the core technologies ofFourier transform spectrometer. Speed uniformity of moving mirror has a direct impact on theperformance of the instrument. For the application of different platforms, moving mirror isrequired to scan at different speed mode. Technical requirements, program design, systemimplementation and performance test results of moving mirror control system are discussed inthis paper.A general control system of multi-speed mode of moving mirror is completed.Firstly, some typical moving mirror control systems of Fourier transform spectrometer areinvestigated. Their mechanical structure, control method, movement mode and measuring deviceare analyzed. The feasibility of multi-speed mode scanning with the same mechanical and opticalstructure is confirmed.Then the impact on instrument performance of moving mirror’s parameters, such asdisplacement, speed, speed uniformity and etc. are analyzed. Possible impact of raising andreducing moving mirror’s speed is discussed. On the basis of research and analysis, technicalrequirements and overall program of moving mirror movement are determined. This paperintroduces the design of speed measurement, motion control, motor drives and other modules,focusing on analysis of control algorithm of moving mirror motion. According to the theory andtechnology of automatic control, a complex control algorithm is presented which uses integralseparation PID as the core, mixed with fuzzy control and feedforward control.The implementation of system hardware and software is described in this paper, includingmovement actuator of moving mirror, reference laser interference system, motion controlmodule, drive module of moving mirror, control algorithm and PC software.The research results show that multi-speed mode scanning technology of moving mirror isfeasible. The control system can realize real-time monitoring and control of moving mirror’sentire movement process. Different speed modes can be switched with good speed uniformity and strong robustness. Further, the causes of speed fluctuation are analyzed and ways ofreducing disturbance are discussed. The results obtained in this paper contribute to establishcomplete theory of Fourier transform spectrometer. |
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