振动条件下成像系统与载体联接参数优化设计

Optimal design of joint parameters between imaging system and basement under vibration

载体振动是制约飞行器上光机系统成像像质的主要因素之一,目前针对这一问题的研究集中在优化系统内部支撑固定结构和设计外部附加减振装置等方面,而对于载体与成像系统之间联接参数方面的改进较少。联接参数不仅在静力载荷作用下影响结构的受力状态,还决定了机械子系统的模态和振动条件下系统的响应位移量。首先通过分析静力和振动条件下光学元件变形量受联接位置参数、角度参数的影响,建立了联接参数同系统动态像质的影响关系,进而提出了以成像系统光学传递函数(MTF)为优化目标的振动条件下联接参数优化方法,最后通过某成像系统实例说明:在不改变系统内部光机结构、不增加外部减振装置的前提下,系统优化后的各视场动态MTF同设计值相比综合下降率不到7%,即在给定随机振动条件下系统可获得无模糊的图像。

The vibration of basement is one of the key factors to restrict imaging quality of optomechanical system on the aircraft. Studies concerning this problem are mainly focused on the optimization of internal support fixed structure and the design of additional external damping substructure. Few studies were on the joint parameters between imaging system and basement. The joint parameters can affect not only the strained condition under the static loads, but also the vibration mode of mechanical subsystem and the receptance of system under a vibration. Firstly, the relationship between the joint parameters and dynamic image quality was established by analyzing the deformation of optical elements under the static and vibration conditions. Secondly, it was presented that the optimization design of the joint parameters in which the optimization target is set as the optical modulation transfer function （MTF） of the system under vibration. Finally, the dynamic MTF of imaging system declines comprehensively all fields of view less than 7% compared with the designed MTF illuminating by an example, without changing the internal optomechanical structure and increasing the external damping subsystem.