Airborne electro-optical/infrared reconnaissance systems could scan a large area by using an array detector and stitching the image sequence to produce a large area coverage image. During the scanning and imaging process, the reconnaissance system may experience various disturbances that can result in the failure of stitching ground area images. To investigate the suppression method of disturbance and achieve seamless area coverage, we first introduce the standard coordinate systems and conversion relationships used in Geo-scanning imaging. We describe the basic implementation of Geo-scanning ground imaging coverage and highlight the problems encountered in achieving seamless ground area coverage. To ensure seamless ground coverage, Geo-scanning uses compensating angular rate commands for cross-roll and pitch scanning gimbal. The process of Geo-scanning is then simulated in the simulation platform and the effectiveness of the designed perturbation suppression method is verified. The feasibility of suppressing multiple perturbations simultaneously is verified. A unified angular rate compensation command is proposed to suppress the effects of forward motion, heading static angular disturbance, and attitude tilt. This will avoid the need for different compensation command expressions for different perturbations and enable resistance to multiple perturbations simultaneously. The proposed method will make the angular rate command for platform scan imaging more robust and avoiding image stitching cracks, ensuring smooth image stitching from a motion control perspective and achieve seamless area coverage.

This paper proposes a Line-of-Sight (LOS) inertial stabilization and pointing control strategy for a 3-DOF Optoelectronics system with mirror. The inertia angular rates of azimuth, elevation and roll of LOS cannot be measured by gyro directly due to the coordinate of LOS is not physically existed. According to the geometric relationship of three gimbals and the law of light reflection, the kinematic equation of LOS is deduced, and an improved installation solution of 4 gyros is proposed to measure the motion of LOS. Then, the LOS system multi-input multi-output (MIMO) model can be established by decoupling 3 orthogonal inertia angular rates of LOS, the angular motions of 3 axis motors, and the measured angular rates of 4 gyros. In addition, by adopting the fully decoupled 3 axis joint control method, the influence of angular disturbances to LOS inertia motion can be mitigated, then 3-DOF inertial stability and precise pointing control of the LOS can be achieved. Furthermore, a dimension reduction control method is proposed to avoid motor over-speed near the gimbal lock orientation, achieve the omnidirectional stabilization of LOS. Simulation and experimental results verify the advantages of the proposed method.

针对二维陀螺平台方位瞄准线控制在过顶位置时因驱动轴和敏感轴存在非线性约束导致的不稳定问题,分析了不同类型扰动源对方位瞄准线稳定的影响及其随俯仰角变化的规律,提出了基于扰动源分类控制的过顶稳定方法.该方法采用反馈和前馈双通道复合控制结构,在过顶位置时基于控制结构自身消除陀螺测量噪声放大导致的内生力矩扰动,通过增加前馈通道的滤波环节,抑制横滚扰动高频分量引起的力矩扰动,解决了过顶位置时方位驱动轴震荡的问题,同时通过反馈通道和前馈通道分别实现对方位扰动和横滚扰动低频分量的有效隔离.仿真结果表明,该方法能够大幅衰减陀螺测量噪声和横滚扰动高频分量引起的方位电机力矩扰动幅值,增强系统稳定性.最后通过某二维陀螺平台进行了实验,过顶位置时瞄准线方位经受振动条件下的稳定精度由82.4 μrad 减小为44.6 μrad,经受摇摆条件下的隔离度由?14.54 dB提升至?27.85 dB.实验结果验证了该方法能够有效提升过顶位置方位瞄准线的扰动隔离性能.

为分析飞机前向运动对光电稳瞄系统扫描策略的影响,介绍与稳瞄系统相关的地心地固坐标系、导航坐标系、机体坐标系、瞄准线坐标系等4种常用坐标系,归纳了常用坐标系之间的齐次变换关系.从微分运动的角度,用运动学表达式论述了载机前向运动对两轴四框架稳瞄系统所产生的成像机理.搭建从稳瞄系统内部控制元件一直到系统外部地理指向的全链路仿真模型,并根据运动学关系在模型中施加相应的控制作用,以消减飞机前向运动对稳瞄系统所带来的成像影响.给全链路仿真模型赋予和物理实际相符的电学和运动学参数,模拟了稳瞄系统在空中对地定位和扫描的过程.结果 显示,该前向运动理论分析正确且有效,所搭建的全链路模型可用.

将四元数相关理论应用于光电稳瞄系统的瞄准线指向研究,从四元数的角度描述了光电稳瞄系统随载体的一般三维运动,分析了载体的一般三维运动对光电稳瞄系统瞄准线的影响,结合所搭载载体的惯导数据,求解了经历载体运动后载体导航系下光电稳瞄系统要保持指示目标所需调转到的三轴姿态角度.以机载光电稳瞄系统为实例对该求解方法进行验证,仿真结果表明:使用该求解方法得出的姿态四元数结果能正确地将瞄准线矢量旋转并指示原目标.

Active Disturbance Rejection Controller (ADRC) is used in the current loop of a miniaturized electro-optical stabilized system. In addition to current loop, the method uses an improved auto disturbances rejection. The method uses classical adjust elements series connected with non-linear feedback adjustment to design control system. The frequency response data of a miniaturized electro-optical stabilized system show that the method can be applied in engineering field and the method is more adaptive than classical ADRC.