气动光学效应波前畸变的光电校正方法研究

发布时间：2018-05-05 22:05

本文选题：气动光学 + 有限元分析　；参考：《北京理工大学》2015年硕士论文

【摘要】：在航空航天领域中，科研工作者对速度有着越来越高的要求使得超高声速飞行器成为近年来的研究热点之一。高声速飞行器上的红外成像制导在现代战争中起着举足轻重的作用。当红外制导的导弹在大气中高速飞行时,其光学头罩表面将受到大气气流的影响而产生严重的气动光学效应，头罩周围的湍流流场以及光学窗口的受热变形都将对来自目标的光波波前产生动态扰动,使成像探测器中目标图像发生偏移、抖动和模糊，，降低光学头罩导引头对目标的探测、跟踪与识别能力。因此，要想达到高速飞行器上红外成像制导的精度要求，就必须对气动光学效应进行控制和校正。气动光学效应的校正主要是从它的成因入手，如进行湍流控制、图像复原、头罩设计、致冷以及采用光电方法校正。在光学窗口外的层流、湍流对光线传输的影响方面已有大量研究，本文针对影响成像光波波前的另一因素光学窗口热变形导致的波前畸变进行了仿真研究，实时波前校正的自适应光学技术是光电校正方法中非常重要的一种，也是本文研究的重点。同时，本文还介绍了光学窗口气动力及热流密度的计算方法以及传热学和弹性力学中热和结构的分析方法。通过对光学窗口的气动热辐射效应和气动热效应进行深入研究，根据载荷及边界条件，利用有限元分析方法对光学窗口进行了热-结构耦合分析，从而计算了红外窗口从导弹发射到击中目标整个过程中窗口的温度场变化及窗口变形。根据分析结果，采用光-机-热集成的方法计算在不同角度的光线入射的情况下，由光学窗口温度变化引起的窗口变形对成像质量的影响。最后。对基于随机并行梯度下降算法的像清晰化自适应光学系统进行了仿真研究。在MATLAB环境下，实现了SPGD算法；在光学设计软件ZEMAX中建立了一个自适应光学系统模型，并通过DDE技术实现MATLAB与ZEMAX之间的通信。由MATLAB计算出变形镜各致动器的电压并传送给ZEMAX，ZEMAX根据收到的电压调整变形镜的形状，计算变形镜形状改变后的点扩散函数(PSF)数据，并传回给MATLAB进行下一步迭代，直至达到满足迭代结束的条件。
[Abstract]:In the field of aeronautics and spaceflight, researchers have higher and higher requirements for speed, so UHV has become one of the research hotspots in recent years. Infrared imaging guidance on hypersonic vehicle plays an important role in modern warfare. When the infrared guided missile is flying at high speed in the atmosphere, the surface of the optical hood will be affected by the atmospheric air flow, which will produce serious aero-optical effects. The turbulent flow field around the hood and the thermal deformation of the optical window will cause dynamic disturbance to the front of the optical wave from the target, which will make the image of the target shift, jitter and blur in the imaging detector, and reduce the detection of the target by the optical hood seeker. Ability to track and identify. Therefore, in order to achieve the accuracy requirements of infrared imaging guidance on high-speed aircraft, the aero-optical effect must be controlled and corrected. The correction of aero-optical effect is mainly based on its causes, such as turbulence control, image restoration, hood design, cooling and photoelectric correction. A lot of researches have been done on the effect of laminar flow and turbulence on the light propagation outside the optical window. In this paper, the wavefront distortion caused by the thermal deformation of the optical window is simulated, which is another factor that affects the wavefront of the imaging light. The adaptive optics technology of real time wavefront correction is one of the most important methods of photoelectric correction, and it is also the focus of this paper. At the same time, the calculation method of aerodynamic force and heat flux of optical window and the analysis method of heat and structure in heat transfer and elastic mechanics are also introduced in this paper. The thermal radiation effect and aerodynamic thermal effect of the optical window are studied in depth. According to the load and boundary conditions, the thermal-structural coupling analysis of the optical window is carried out by using the finite element analysis method. Thus, the temperature field and window deformation of the infrared window during the whole process from missile launching to hitting the target are calculated. According to the analysis results, the influence of window deformation caused by the temperature change of optical window on the imaging quality is calculated by the method of opto-mechanical-thermal integration under the condition of different angles of light incidence. Finally. The image clarity adaptive optical system based on stochastic parallel gradient descent algorithm is simulated. The SPGD algorithm is implemented in MATLAB environment, and an adaptive optical system model is established in the optical design software ZEMAX, and the communication between MATLAB and ZEMAX is realized by DDE technology. The voltage of each actuator of the deformable mirror is calculated by MATLAB and transmitted to ZEMAX / ZEMAX according to the received voltage to adjust the shape of the deformable mirror, and the point diffusion function (PSF) data after the shape of the deformable mirror is calculated, and the data is transmitted back to MATLAB for the next iteration. Until the conditions for the end of the iteration are met.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V448.2;V419

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