No abstract

The control system design and experimental investigation of the gas regulating system for a ducted rocket are studied in this article. First, the dynamic model of the gas regulating system for the ducted rocket was established, and comparison of the two regulating modes regarding non-linearity and uncertainty was done. In contrast with the area-regulated mode, the non-linearity of the pressure-balanced mode is smaller and the robustness is stronger. Then, the study of the the gas control system is performed based on the model established in this article. The introduction of high-gain feedback suppresses the effects of non-linearity and uncertainty in the pneumatic servo system. Also, a proportional-integral controller for the gas regulating system based on linear matrix inequality is designed. Lastly, an experimental investigation of the gas flow control system is done to verify the validity of the gas control system. The experimental result shows that the gas flow control system has good performance. The turndown ratio of mass flow through the control valve was up to 3.7:1.

The direction rule of the laser beam traveling through a deflected polarizing beam splitter (PBS) cube is derived. It reveals that, due to the influence of end-face reflection of the PBS at the detector side, the emergent beam coming from the incident beam parallels the direction of the original case without rotation, with only a very small translation interval between them. The formula of the translation interval is also given. Meanwhile, the emergent beam from the return signal at the detector side deflects at an angle twice that of the PBS rotation angle. The correctness has been verified by an experiment. The intensity transmittance of the emergent beam when propagating in the PBS is changes very little if the rotation angle is less than 35 deg. In a 3D imaging lidar system, by rotating the PBS cube by an angle, the direction of the return signal optical axis is separated from that of the origin, which can decrease or eliminate the influence of direct reflection caused by the prism end face on target return signal detection. This has been checked by experiment.

No abstract