【作者】 周剑；

【导师】 于起峰；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2012， 博士

【摘要】 导弹、炮弹等武器飞行的外弹道及姿态等参数是武器试验鉴定及故障分析的基本依据。武器试验靶场一般利用布置在若干固定点位上的多台光电经纬仪或高速摄影(像)机等光学测量设备，分别对目标进行跟踪拍摄，多站交会测量目标的外弹道与姿态等参数。但这种固定式测量方式作用范围有限，不能灵活机动布站，为了满足具有大航程、长航时、机动性强等特点的现代武器的观测需求，靶场光学测量方式正逐步从固定式向机动式发展，如车载经纬仪采用机动布站、定点测量方式，机载光测设备直接采用机动测量方式。然而，在这些车载、机载平台上利用光学设备对运动目标实施观测还存在一些困难，其中主要有：车载经纬仪根据测量任务设置站点，其地基无法保证像固定站点般稳固，使得车载平台较易产生晃动，导致车载经纬仪难以获得高精度的测量结果；受飞机自身结构、尺寸等限制，在单架飞机上通常不能形成有效的多站交会条件，使用多机联合测量的成本又过高，现有条件下只能利用机载光测设备对运动目标跟踪拍摄，记录其飞行过程，无法测量目标的外弹道与姿态。这两个困难引申出了摄影(像)测量技术的两类基本理论问题：一类是在晃动平台(不稳定平台)上观测运动目标的问题，另一类是在机动平台上利用单站光测设备获取运动目标的轨迹与姿态的问题。本文统称这些在晃动和机动平台上利用光测设备对目标实施观测的问题为动平台光学测量问题。针对在上述动平台上实施光学测量的问题，本文分别提出了不稳定测量平台的静态基准转换方法解决平台晃动引起的车载经纬仪测量误差的问题，以及单目运动轨迹交会方法解决机动平台上单站光测设备对目标定位与定姿的问题，为解决目前国内靶场动平台上光测设备只能观察记录，不能高精度测量等问题提供了新的技术手段，也可适用于其它领域的类似测量问题，如不稳定测量平台的静态基准转换方法可应用于船体变形测量、机动雷达水平误差修正等领域，单目运动轨迹交会方法可应用于坦克对移动目标的定位等领域。论文的主要工作及创新点如下：1.针对不稳定平台上的观测设备无法对运动目标实施高精度测量的问题，提出了一种基于传递像机的不稳定测量平台的静态基准转换方法。该方法通过构造一个静态基准，采用摄像测量方法，建立不稳定测量平台与静态基准的关系，消除平台不稳定引起的观测设备测量误差，即相当于将不稳定测量平台转换到一个静态基准上。该方法的基本要素包括：测量不稳定平台的晃动量，如可将固定在地面上的合作标志物作为静态基准，利用安装在不稳定平台上的传递像机拍摄这个静态基准来获得该晃动量，也可以将传递像机置于地面上作为静态基准，拍摄固定在不稳定平台上的标志物来获得这个晃动量；标定传递像机与平台，或标志物与平台间的固联关系。2.将不稳定测量平台的静态基准转换方法应用于靶场的车载经纬仪等设备，设计了一种车载经纬仪动态误差测量与修正系统，解决了合作特征受遮挡、出视场等受干扰情况时的位姿估计、车载经纬仪的车载平台与像机固定关系标定、经纬仪测角数据误差修正等实际工程问题，在车载经纬仪上完成了一系列验证实验和实测任务实验，得到了实测过程中两种不同型号的车载经纬仪平台姿态变化量，据此修正了多次任务中车载经纬仪的测角数据，提高了利用多站测角数据交会获得的三维外弹道数据的精度。3.利用现有的位姿估计方法测量车载经纬仪晃动时，对合作标志上特征的空间几何关系测量精度以及像机参数标定精度都有较高的要求，在车载经纬仪动态误差测量与修正系统的实施过程中不易满足。为此，提出了一种简化配置条件下车载平台姿态变化的测量方法。该方法通过两组垂直布置的测量单元(每个测量单元由一台像机和两个合作特征点组成)分别对平台两个方向上的高低和方位变化进行测量，进而得到平台的三维姿态变化量。4.针对在飞机等机动平台上光测设备对目标单站定位的问题，提出和完善了一种运动单像机对运动目标定位的方法，即单目运动轨迹交会法。该方法突破了传统摄像测量的点交会模式，用参数化方程描述某一时间段内目标的运动轨迹，通过直接求解线性方程组得到目标运动轨迹方程参数，进而得到目标的三维位置、速度、加速度等运动参数。推导了该方法有解的充分必要条件，给出了目标轨迹方程最优阶次的确定方法，以及该方程能够最优描述的目标轨迹的时间段长度的确定方法。5.针对在飞机等机动平台上光测设备对目标单站定姿的问题，在单目运动轨迹交会法的基础上，提出了一种单目运动像机对运动目标的定姿方法。该方法通过对目标上的若干特征点进行跟踪测量，先获取其三维运动轨迹，再根据这些特征点的相互关系，解算目标的三维姿态变化，并以这些特征点的间距不变等约束条件为准则优化目标姿态结果。更多还原

【Abstract】 The ballistic trajectory and pose parameters of the flight object such as missile,shells, which are the basic evidences for the assessment of weapon test and failureanalysis, are measured with intersection method by multiple Optical measurementequipments such as photoelectric theodolite and high-speed photography camera(vidicon) which are placed at fixed point and are used to track and shoot the object. ButThere are some shortcomings of this kind of fixed measurement method, includingfixed effective range, no flexibility, etc. In order to satisfy the measurement demand ofmodern weapons with long-distance and long-time flight, strong maneuverability,optical measurement mode in shooting range gradually develop from the fixed one tothe mobile one, such as vehicle theodolite which works with the mode of mobilesetting,pointing measuremet, airborne optical measurement which can measure in flight.However, there are some difficulties in moving object observation by the opticalequipments fixed on vehicle and airborne platform, mainly including: Thegroundwork of vehicle theodolite, which have to satisfy measurement demand, can’tassure as steady as the one of fixed theodolite, hence, the vehicle platform is easy toproduce a wobble which makes the theodolite difficult to obtain high accuracymeasuring results. Usually, with the limit of the structure and size, a single planecan’t form valid intersection measurement conditions, it cost too much to prepare moreaircraft which calculate the results with intersection method. Currently, a singlemeasurement equipment in an airborne platform can only shoot the object and recordthe image in flight, but can not obtain the trajectory and pose parameters. Two kinds ofbasic theory problem of photogrammetry(videometrics) can be summarized from thetwo difficulties: one is moving object observation problem on disturbedplatform(unstable platform), the other one is moving object observation problem bymonocular camera on mobile platform. The optical measurement problems on unstableplatform and mobile platform are also named as “optical measurement problems onmoving platforms”, together.In order to conquer the optical measurement difficulties on moving platforms,“conversion method for unstable platform to static reference” is proposed to eliminatethe unstable platform caused measurement error in vehicle theodolite application, and"monocular trajectory intersection method" is proposed to implement the trajectory andpose measurement of moving objects by monocular camera on mobile platform. Themethods not only provide new techniques for optical measurement equipments, whichcan only look and record the moving procedure of the object, but can not to get highprecision measuring results, in the current domestic range, but also can be applied toother fields of similar measurement problems, for example,“conversion method for unstable platform to static reference” can be applied to ship deformation measurement,correction of mobile radar level deformation measurement error and other fields,"monocular trajectory intersection method" can be applied to moving targets positioningon tank, etc. The mainly work and innovation points of the dissertation are as follows:1.“conversion method based on relay cameras for unstable platform to staticreference” is put forward to achieve high accuracy measurement of the movement targeton unstable platform. In this method, a static reference is constructed, the relationshipbetween the reference and unstable measurement platform is measured by videometrics,then the error which is caused by unstable factor of the platform can be eliminated, i.e.,the unstable measurement platform is converted to a static reference. The basicelements include: the measurement of the wobble of the unstable platform, forexample, the wobble can be obtained by shooting a cooperation structure fixed on theground as a static reference with cameras put on the unstable platform, as well as byshooting a cooperation structure put on the unstable platform with cameras fixed on theground; the calibration for the relationship between the relay cameras and platform,or between cooperation structure and platform.2. A measurement and correctness system based on “conversion method based onrelay cameras for unstable platform to static reference” for dynamic errors of vehicletheodolite is achieved. A lot of engineering problems such as pose estimation under thecircumstance of cooperation markers which are coverd or kept out, the calibration forthe invariable relationship between the relay cameras and platform, correctness of anglemeasuring data of theodolite,etc. A series of validation experiments and experiments insome practical tasks, which obtain the platform pose variation of two differenttheodolite, and amend angle measurement data, are accomplished and improve theprecision of3D ballistic trajectory.3. Some requirements are not easy to be satisfied when use existing poseestimation methods to measure the theodolite wobble, such as the precision of the spacegeometric relationships between markers in cooperation structure, the precision ofcalibration for cameras, etc. Therefore, a pose variety measuring method for vehicletheodolite platform under simplified configuration conditions is proposed. Thevariations of pitch and yaw angle in two directions, which compose the3D posevariation of the platform, are detected through the two measurement units (eachmeasuring unit is composed by a camera and two cooperate feature points), respectively.4. A positioning method for the moving object by a moving monocular camera, i.e.,"monocular trajectory intersection method", is proposed and improved for opticalmeasurement equipments in airborne platform. The method breaks through thetraditional "point meet" mode, describe one object trajectory in a period of time withparametric function, and get these parameters by solving a set of linear equations directly, then calculate the position, speed, acceleration of the object. The necessary andsufficient conditions are given, and the methods which can confirm the optimal order ofthe parametric function and the best length of time which make the function be the bestto describe the object trajectory in this period of time.5. A pose estimation method for the moving object with a moving monocularcamera by extending "monocular trajectory intersection method" is proposed for opticalmeasurement equipments in airborne platform. The method get the trajectory of severalfeatures in an object by "monocular trajectory intersection method", and get the posevariation of the object according to the mutual relationship of these features, and theinvariability of these features such as the distance is as a criteria for pose optimization.更多还原