潜载光电跟瞄系统电磁力消涡滤波的机理研究

Optronic mast is a significant tracking-aiming equipment for the submarine-based laser weapon systems. When the submarine navigates with high velocity, the fluctuations of the boundary layer velocity and pressure could increase the input noise of the tracking-aiming system, owing to the vortex induced vibrations and the disturbing moment. However, the current hardware and digital filters couldn’t achieve higher precision due to the bandwidth limitation and time lag. Our research aims at improving the performances of the tracking-aiming system by adjusting the boundary layer and suppressing the noise with Lorentz force. Firstly, the spatial distributions and intrinsic mechanism of the vortex induced vibrations are numerically investigated based on a submarine model with full attachments. Then, the submarine moving tendency is decoupled to the optical axis coordinate system. Moreover, the transfer functions of the tracking-aiming and optical system are designed. Finally, combined with the closed-loop control strategy, simulations of this control system are conducted to assess the control effects. The application methods of the Lorentz force could be further optimized according to the simulation results and flow analysis. This project would provide more theoretical basis for the engineering applications of the Lorentz force on suppressing vortex induced vibration as well as improving the tracking performances for the submarine-based optronic mast.

光电桅杆是潜载激光武器重要的跟瞄装备。当潜艇在水下高速行进，边界层所导致的壁面脉动以及压差力会诱发较大的涡激振动和力矩扰动，导致跟瞄系统输入噪声的增加。现有的数字和硬件滤波由于其带宽的局限性和时滞性，不能满足更高精度的要求。以壁面电磁力边界层调控、抑制潜艇流噪声、提高潜载跟瞄系统性能为目的，本课题拟首先通过数值分析探讨均匀来流条件下，诱发全附体潜艇及光电桅杆涡激振动的内在机理和分布形式，并研究壁面电磁力对潜艇及各附体场强分布、涡街演化和运动趋势的影响；其次通过解耦将潜艇运动趋势转换到视轴坐标系中，并建立粗精两级光电跟瞄装置的控制与光学系统传函；最后配合合适的闭环控制策略，通过控制系统仿真评估电磁力消涡滤波对提高光电系统跟瞄动/静态性能的作用效果，以此为评价依据结合流动分析反推最优的电磁力作用方式。本项目的开展将为电磁流动控制在降低潜艇噪声、提高潜载跟瞄装置跟踪性能等方面的应用提供理论依据。

研究背景：光电桅杆是潜载激光武器重要的跟瞄装备。当潜艇在水下高速行进，边界层所导致的壁面脉动以及压差力会诱发较大的涡激振动和力矩扰动，导致跟瞄系统输入噪声的增加。现有的数字和硬件滤波由于其带宽的局限性和时滞性，不能满足更高精度的要求。因此本项目先从航行器壁面电磁流体控制着手进行了分析。.研究内容：（1）以壁面电磁力边界层调控、抑制方式来调控潜艇的流噪声、提高潜载跟瞄系统性能为目的，本课题首先通过数值分析探讨均匀来流条件下，诱发全附体潜艇及光电桅杆涡激振动的内在机理和分布形式，并研究壁面电磁力对潜艇及各附体场强分布、涡街演化和运动趋势的影响；（2）其次通过解耦将潜艇运动趋势转换到视轴坐标系中，建立了“FSM+转台”和“FSM+音圈电机+转台”型粗精多级光电跟瞄伺服转台，获得了相应执行机构的传递函数模型与光学系统传函模型；（3）并分析了不同海况下潜行和水面漂浮时，艇身扰动对光轴扰动误差的影响。对比分析了不同控制模型（干扰观测器、分数据PID控制器、姿态扰动滤波方法、基于Singer模型的kalman分析）等多种滤波和伺服转台控制策略。（4）最后以定向能武器为研究对象分析了Exocet等三种反舰导弹来袭过程中，不同随动控制测量下，潜载定向能武器对来袭目标的毁伤效能。.主要结论：电磁力不同作用区域—半球形艏部与艇身过渡处、潜艇围壳顶盖、潜艇围壳周围其削涡作用有较大的差异，在艇体楞缘处其脉动较大，影响较为剧烈，因此这些区域施加电磁力减振效果最好。电磁力对潜航器的减阻滤波能显著地提升其光电跟瞄装置稳定跟踪精度；但是潜载随动系统的平台架构、控制策略、滤波算法以及载体的扰动特征对其最终的跟瞄性能也有较大的影响。