周视大像旋稳海天线方位截距补偿算法

Compensation algorithm for azimuth intercept of panoramic image rotation stabilizing sea-sky line

为使两轴周视光电探测系统在三自由度扰动和大像旋条件下搜索并跟踪水面目标,在虚拟天际线焦平面像五自由度解析表达式基础上,推导出以目标像点和像旋中心线距离作为补偿截距的周视大像旋稳海天线方位截距补偿算法。通过对补偿截距与系统焦距的比值求反正切函数得到补偿角的绝对值,将目标像点和像旋中心点坐标转换到方位旋转坐标系下,并以转换后二者横坐标的代数差正负号作为补偿量的符号判据。该算法是在存在非线性大角度像旋情况下使目标像点逼近像旋中心线,与俯仰机构的向量角补偿算法联动能够使目标像点始终逼近焦平面原点。数学模型仿真验证了单次补偿能够将残差减小到1%左右,真实工况试验也验证了方位截距补偿算法的合理性。

For a panoramic optoelectronic detecting system to compensate three disturbances to track offshore targets by azimuth and pitching axes,based on a five dimensional analytical expression for a image line projected on focal plane,a compensation algorithm for azimuth intercept of panoramic image rotation stabilizing sea-sky line,which takes target point and image rotation centerline as the compensation intercept,is derived.The absolute value of the compensation angle is obtained by extracting the arc tangent function for the ratio of the compensation intercept and system focal length.The coordinators of the target image point and image rotation center point is converted into the coordinator of azimuth rotation.The algebraic difference sign for the abscissa of the two points is taken as the sign criterion of the compensation dosage.The algorithm allows the target image point to approach to the image rotation centerline in the case of the nonlinear large-angle image rotation,and always approach to the original point on the focal plane in combination with the compensation algorithm of the vectorial angle for the pitching mechanism.The simulation of the mathematical model shows that a single compensation can reduce the residual by a factor of 1%.The reasonableness of the compensation algorithm for azimuth intercept was proved by an actual condition test.