基于磁流体动力学的宽频惯性基准关键问题研究

Along with the range of detection further improving, the extremely high requirements to the pointing precision of sensitive load are proposed in the field of aeronautics and astronautics. The interference of wide band micro-angular vibration should be considered to enhance the stability and tracking accuracy of the inertial reference. Setting up a new generation of high-precision wide-band inertial reference has become the key to the technology of high-precision remote sensing and line-of-sight stabilization. However, the study of wide-band inertial reference in our country is still at the primary stage. Some key technologies such as the micro-angular vibration measuring, support structure, control method and the drive method still need a breakthrough. The research of the project will be based on the existing MHD (Magnetohydrodynamics, MHD) angular velocity sensor. Firstly, how to obtain the wide-band angular vibration information is studied. Secondly, the design criteria of flexible support under multiple constraints is built. Thirdly, the control strategy of velocity-position loop is optimized. And then, the driving principle and technology with large stroke and rapid response is explored. Finally, A new generation of wide-band inertial reference with high precision tracking and vibration isolation will be achieved. The research of this field is of great significance for deep space exploration and development of directional guidance weapons.

随着探测距离的进一步提升，航空航天领域对敏感载荷的指向精度提出了极高的要求，因此必须考虑宽频带微振动干扰的影响，进一步提升惯性基准的姿态稳定度和跟踪精度。建立新一代高精度宽频带惯性基准已成为高精度遥感和视轴稳定技术研究的关键。然而我国对宽频惯性基准的研究还处于初级阶段，一些关键技术如微角振动测量、支撑结构、控制方法和驱动途径等方面的研究仍有待突破。本项目拟在前期研究磁流体动力学（Magnetohydrodynamics，MHD）宽频带角振动测量仪器的基础上，采用MHD角速度传感器与陀螺仪组合测量的方法，获取宽频带高精度角振动信息，研究多约束条件下的宽频带惯性基准柔性支撑结构设计准则，优化速率-位置双环惯性基准控制系统的控制策略，探索大行程、快速响应的驱动原理及技术，最终实现新一代惯性基准的宽频带高精度跟踪及振动隔离。该领域的研究工作对开展深空探测和开发激光定向能制导武器具有重要意义。

惯性基准是一个可实现两个方向小角度偏转的平台，其上安装有低噪声、宽频带惯性传感器组，反馈控制位于两个正交方向上的推拉驱动机构，实现平台上参考光束的高精度稳定。基于惯性基准的视轴稳定方式是克服动载体光电跟瞄系统高频扰动，实现微弧度甚至亚微弧度级跟瞄的主要技术手段，在对地观测、深空探测及激光通信等领域有着广泛的应用。国内惯性基准的扰动抑制带宽和稳定精度与国际先进水平相比存在较大差距，无法满足激光通信对准精度和制导武器毁伤效率提升的迫切需求。.本项目旨在突破宽频惯性基准传感、支承、驱动、控制四个方面的技术瓶颈，为动载体光电跟瞄系统的精确指向与对准构建技术。项目提出了闭合环形腔内非定常流场与不均匀磁场的耦合数值仿真方法、利用测量协方差辅助信号频率判定的频域分段型自适应卡尔曼信号融合方法、高磁场均匀性的复合轴向磁路设计方法、基于不完全PID/扰动抑制DOB的复合位置控制算法及速度内环-位置外环稳定性解耦式的稳定控制方案，建立了考虑应力集中效应的圆柱型柔性铰链解析柔度模型，分析了各向柔度随关键尺寸参数变化的规律，建立了MHD执行器的传递函数模型，分析了MHD执行器中二次流、诱导磁场和非均匀磁场等误差源对驱动器性能的影响，设计了MHD执行器原理样机和基于混合级联多电平拓扑结构的驱动器。成功研发了转角范围大于±5mrad、线性度优于0.2%、迟滞小于0.06%、重复定位精度和角分辨率均优于1μrad的宽频惯性基准原理样机。项目研究内容可为我国突破动载体高精度跟瞄领域的国际封锁提供理论和技术支撑。