分析了随机振动对调制传递函数的影响,指出角位移是影响航空成像质量的主要因素.研究了特定条件下可容许的MTF下降,并转变为稳定系统的设计参量,用来指导稳像系统的设计.利用空间机构学及平行四边形平动原理,研制了一种新的无角位移减振稳像平台,满足既无角位移又达到减振要求.根据设计理论给出了设计实例,对频率高于100 HZ的振动,衰减达34 dB,并利用动力学软件进行测试仿真,仿真曲线验证无角位移减振的正确性,同时对无角位移机构进行光学测试,结果耦合角度小于8″,可以满足航空成像要求.

Modulation transfer function (MTF) resulting from random vibration was analyzed.The effect angular displacement was regarded as major factor to affect the image of aerial camera.Allowable MTF degradation was represented,and allowable MTF degradation was converted into stable system design parameters.The parameters can guide perfect design for stabilization system.Based on the spatial mechanism and translational principle of parallelogram,an irrotational displacement isolator was developed,which can meet the requirements of irrotational displacement and damp.An instance was given,and 34 dB reduction was achieved at frequency of 100HZ.With the help of MSC.ADAMS simulation software,curve proves correct for isolator was simulated,and the irrotational displacement mechanism was tested by optical method with coupled angle being less than 8″,which can satisfy the demand of aerial imaging.