针对船载精密成像系统在船体晃动时产生的杆臂牵连平动和等效圆锥旋转, 提出了一种将惯性量测信息引入电子稳像技术对耦合干扰进行补偿的方法。首先, 基于俯仰-偏航式光学稳定平台分析其在视线稳定过程中所产生的等效圆锥旋转, 推导了视线旋转角与平台转角之间的数学关系。然后, 分析了杆臂牵连平动对像点虚化的影响, 并结合圆锥旋转构建了耦合扰动模型; 针对耦合扰动模型提出利用惯性测量信息复合电子稳像的方法来实现低特征背景下的高精度稳像。最后, 通过半实物仿真验证了该方法在低特征环境中的成像稳定精度和实时性。结果显示: 提出的方法能够有效补偿俯仰-偏航式稳定平台转动以及船体晃动时形成的耦合干扰, 在低特征环境中具有较高的成像稳定精度和实时性, 修正误差为亚像素级。图像稳定后的峰值信噪比平均提高了4 dB, 基本满足船载光学精密探测系统对实时性、精度、抗干扰能力和稳定性的要求。

For the lever arm translational motion and equivalent coning rotation of a ship-borne optical detection system under a great hull attitude, a compound Electronic Image Stabilization(EIS) method which brought inertial information was proposed to compensate the coupled disturbance. Firstly, the equivalent coning rotation existed in the LOS (Line Of Sight) stabilization process was analyzed based on a pitch-yaw optical stabilization system, and the relationship between LOS rotation angle and platform roll angle was deduced. Then, the influence of lever arm disturbance on weak spots was analyzed and a coupled disturbance model combined with the equivalent coning rotation was built. On the basis of the model, a compound image stabilization method by combing inertial information and the EIS method was proposed to realize the image stabilization under a low characteristic environment. Finally, the image stabilization and real time ability of the proposed method were verified through hardware-in-the-loop simulation under the low characteristic environment. The results demonstrate that the method compensates the coupled disturbance from the lever arm translational motion and equivalent coning rotation. It has higher image stabilization and real time ability, and motion estimation is at a sub-pixel level. After compensation, the peak signal-to-noise ratio (PSNR) of image stabilization improves by 4 dB on average. It satisfies the requirements of ship-borne optical imaging systems for strong instantaneity, high precision, strong anti-interference and stable and reliable characteristics.