无人机载光电平台相对角位移测量与分析研究

	无人机载光电平台相对角位移测量与分析研究
	王子辰
学位类型	博士
导师	戴明
	2014-07
学位授予单位	中国科学院大学
学位专业	光学工程
摘要	无人机载光电平台作为一种优秀的空中侦察、探测系统，在地质勘测、灾害预报、军事侦察与打击毁伤评估等诸多领域发挥着越来越重要的作用。在机载光电平台小型化与集约化的潮流下，实现侦察与打击一体化是未来无人机的发展趋势，而机载光电平台的引导与目标定位精度是实现侦察与打击一体化的关键。国外的光电平台内部集成高精度IMU，平台的视轴稳定、引导与目标定位精度很高；相比之下，国内装备的航空光电平台由于技术原因需要协同光电平台和载机的GPS及INS数据实现相同的功能。一方面，航空光电平台作为空基成像设备，需要安装阻尼减振器来隔离航空发动机高速旋转及振动耦合造成平台成像像质下降的问题；另一方面，由于阻尼减振器的存在，载机飞行时由于侧风、外部气流以及载机姿态等外部因素的影响极易使光电平台与载机间产生微小的相对位移，从而造成目标定位精度下降。因此，对航空机载光电平台与载机间的相对角位移开展研究既是工程的迫切需要，也具有十分重要的理论和现实意义。论文从实际工程中无人机载光电平台安装使用的某型阻尼减振器入手，详细分析了阻尼减振器自身及安装阻尼减振器后光电平台与载机间相对角位移运动特点，结合实际工程经验与平台引导、定位的原理，提出阻尼减振器引起的相对角位移亦是影响当前机载光电平台测量精度的因素；针对线阵相机的特点，论文提出了一种基于虚拟立体靶标的线阵相机标定方法；提出并改进了一种使用组合线阵相机进行机载光电平台相对角位移测量的方法，制作了相对角位移实时测量原理样机，并在实验室条件下开展了相应的测量实验；最后，根据论文测量得到的相对角位移及无人机载光电平台目标定位误差方程，通过对机载光电平台目标定位精度进行深入地分析，验证了论文的研究成果对提高机载光电平台引导与目标定位精度的重要意义。论文主要创新工作和研究成果如下： 1.在机载光电平台的运动特性分析方面，针对目前国内无人机载光电平台安装时使用的阻尼减振器的结构，分析了阻尼减振器及机载光电平台的运动特性，详细分析了安装减振器后光电平台与载机间相对角位移的特点，指出了阻尼减振器引起的相对角位移是影响无人机载光电平台测量精度的主要因素，将有助于后续机载光电平台减振设计及视轴稳定的相关研究。 2. 在线阵相机标定方面，针对线阵相机视场狭窄，传统成像标定过程中标定特征点容易丢失的问题，提出一种基于虚拟立体靶标进行线阵相机标定的方法，并使用并行梯度下降算法对相机参数进行迭代求解，有效解决了传统两步法中速度慢的缺点；同时，对影响标定精度的相对位移进行了误差分析。 3. 在无人机载光电平台相对角位移测量方面，在介绍了刚体相对欧拉姿态角的基础上，针对光电平台与载机间相对角位移的特点，提出并改进了使用组合线阵相机进行相对角位移实时测量的方法，并完成了原理样机的研制。通过在光电平台上安装合作目标点，并结合构建的组合线阵相机测量系统，实现了目标点的空间坐标重建及目标相对角位移的测量。 4. 在无人机载光电平台目标定位精度分析方面，利用坐标变换的原理及蒙特卡罗方法对影响目标定位精度的因素进行误差分析。研究表明，现阶段技术条件下，综合载机的位置、光电平台的姿态角、载机与光电平台的相对角位移、载机的姿态等诸多误差因素，载机与平台间的相对角位移亦是造成现阶段无人机载光电平台目标精度的主要因素；同时，通过仿真分析验证了论文的研究成果对提升现阶段装备的无人机载光电平台目标定位精度具有十分积极的意义。综上所述，论文对现阶段某型无人机载光电平台涉及的相关基础理论进行了分析研究，提出了适于无人机载光电平台的相对角位移测量方法，完成了一套机载光电平台相对角位移实时测量系统样机的研制，实验室条件下实现了无人机载光电平台与载机间相对角位移的精确测量，并将相对角位移测量成果应用于无人机载光电平台目标定位误差计算中，定量地分析了实时测量相对角位移对提升光电平台目标定位精度的意义。论文的相关研究成果对现阶段装备的无人机载光电平台引导、目标定位精度的分析与提升有较大的理论与实际意义。
其他摘要	As an outstanding reconnaissance and detection equipment, opto-electric airborne platform of UAV is used on geology reconnoitering, calamity forecasting, military strike and strike effect estimation prevalently. With the development of miniaturization and intensivism of airborne platform, the development trend of UAV is to incorporate both reconnaissance and strike, which is highly dependent on the precision of platform conduction and orientation. Actually, the precision of LOS stabilization, platform conduction, and orientation is precise because IMU is engaged in airborne platform overseas. However, civil airborne platform need to cooperate with data from airborne platform, GPS and INS for technique reasons. On the one hand, as a kind of airborne imaging equipment, it is very necessary for airborne platform to employ damper to avoid image smear by isolating vibration. On the other hand, a tiny relative angular translation, which caused by crosswind, airflow and attitude of UAV, may be brought between UAV and airborne platform because of the existence of damper, and this will worsen the precision of object orientation directly. Therefore, our researches about the angular translation between airplane and airborne turret are not only very useful theoretically, but also practical specially. All discussions in this dissertation are based on a kind of damper in active opto-electric turret mainly. First, we do some analysis about the inherent and kinetic characters of damper and the affections on orientation due to the relative angular translation between UAV and airborne platform. Second, a method for calibrating line scan camera by proposed virtual stereo pattern is achieved according to the characters of line scan camera. A promoted multi-vision apparatus, composing with nine linear cameras, is designed and accomplished, and several experiments are carried out in laboratory. At last, orientation error is analyzed profoundly according to the precision of measured angular translation and orientation equation, and this orientation error indicates that our research is very significant for turret conduction and orientation. The main innovations and research results are as following: 1. First, in the aspect of airborne platform, we analyze the kinetic characters of platform according to the structure of damper engaged in airborne opto-electric platform presently and the relative angular translation between airplane and turret. In addition, we infer the relative angular translation caused by damper is a very important factor may affect orientation of UAV platform. This will be very useful for isolating vibration in following design and LOS stabilization of airborne payload. 2. In the aspect of calibration of line scan camera, a practical method based on virtual stereo pattern is put forward based on both narrow view plane of line scan camera and easy-missing characteristic point. At the same time, stochastic parallel gradient descent method is used to acquire the parameters of camera instead of traditional time-consuming two-step calibration method, and some error analysis is involved. 3. In the aspect of measuring relative angular translation, many relative attitude measurement methods are introduced and a system for measuring relative angular translation between UAV and airborne platform is designed and manufactured. Besides a compact multi-vision system with nine line scan cameras and three cooperative objects fixing on the turret, we accomplish the coordinate reconstruction of cooperative objects and measure the relative angular translation precisely. 4. In the aspect of object orientation of airborne platform, error analysis is engaged by Monne Carlo strategies under the principle of coordinate transformation. As a result, among all the error factors including position of UAV, the attitude of airborne turret, the relative angular translation between the photoelectric platform and UAV and attitude of UAV, the relative angular translation caused by damper is crucial for orientation. At the same time, our measured results are used in orientation of airborne platform, and it very significant for turret conduction and orientation. In conclusion, this dissertation analyzes many referred technique involving a kind of existing airborne turret. A practical method for measuring relative angular translation between UAV and airborne turret is raised. An applied prototype apparatus is developed, and many experiments are carried out in laboratory. The relative angular translation is measured in lab and measuring results is used in evaluating object orientation error. All these researches will not only benefit the stabilization of LOS, but also can enhance the object orientation precision of tactical UAV airborne platform theoretically and practically in future.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41483
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	王子辰. 无人机载光电平台相对角位移测量与分析研究[D]. 中国科学院大学,2014.

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