【作者】 蒋自成；

【导师】 周建平；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2008， 博士

【摘要】 交会对接技术以其广阔的应用前景已成为保障国家空间技术优势的重要组成部分,有关该技术的研究与发展在空间领域具有紧迫性和前沿性。尽管目前交会对接技术正朝着高水平的自动自主方向发展,但手控交会问题的研究对于载人航天器的空间交会技术突破仍有着极其重要的意义,尤其在自控系统失效后,人的手控操作能力将成为交会对接任务能否顺利完成的关键因素。本文以载人航天器与合作目标的手控交会问题为背景,提出了基于虚拟现实支持手控交会问题研究的新思路,打破了基于平面十字靶标进行手控交会的传统模式,对手控交会过程中的相对运动参数获取、立体场景显示、人的视觉特性等关键问题进行了相关研究。具体工作包括:提出了基于TV图像处理获取相对运动参数的新思路。1)从理论上分析了摄像机的一般成像模型,并根据手控交会时TV摄像机的成像特点进行了模型简化,提高了模型参数计算的速度和稳定性。2)基于两步法详细推导了简化模型参数的求解过程,通过仿真实验验证了简化模型与完整模型之间是基本等价的,模型的简化是合理的,可以基于简化模型进行像机参数的标定以及相对运动参数的测量。3)研究了相对运动参数测量的一般方法,推导了双目测量和单目测量模式下的位姿数据计算方法,给出了仿真结果。4)研究了模糊图像的恢复方法,建立了手控交会时的图像恢复模型,运用逆滤波复原法对退化的图像进行恢复处理,提高了图像质量和测量精度。突破传统可视化的平面模式,实现了场景的立体化,并对场景显示频率进行了优化控制研究。1)介绍了立体视觉模型与双中心投影算法,结合工作实践给出了两种生成立体图像对的软件实现方法,实现了虚拟场景的立体化。2)研究了立体场景显示时的优化控制问题,利用帧间相关性提高了场景的输出频率,并引入场景复杂度的闭环控制方法解决了视点变换时的场景显示频率不稳定问题。分析了基于平面靶标的手控交会策略,对观察平面靶标时产生视觉误差的原因进行了理论研究,提出了解决方案,具有较强的工程实用价值。1)分析了基于靶标图像的手控交会策略,总结了传统手控交会策略的局限性。2)研究了平面靶标的视觉误差产生原因以及对手控操作过程的影响。3)引入立体场景辨别了视觉误差,通过仿真结果证明了立体显示有助于提高操作人员对航天器当前相对运动状态的判断能力,从而能够减少手控过程中的燃料消耗。采用分布式框架实现了基于虚拟现实的手控交会仿真系统。1)基于面向对象的建模方法和可复用设计模式提出了基于虚拟现实的手控交会仿真系统的总体结构与开发层次框架,介绍了各个分系统的设计方案。2)基于该系统分别进行了十字靶标和双通道立体显示环境中的手控交会仿真实验,其结果证明了立体视觉环境中的手控操作人员能获取更多的相对状态,从而有较高的对接成功率。基于虚拟现实展开手控交会技术的研究是一个新思路,也是交会对接相关技术研究领域的一次有益的尝试。论文的工作对我国载人航天二期工程和其他空间应用工程具有实用参考价值。更多还原

【Abstract】 Rendezvous and docking technology is an important part of space technology, and relevant research and development is emergent and necessary for China Manned Space Engineering. Though rendezvous and docking technology can be developed by automatic and autonomous way, manual control rendezvous and docking research is significant for breakthrough of manned spacecraft rendezvous and docking technology. Especially when automatic control system is out of work, maneuverability of spacecraft is key factor for accomplishment of rendezvous and docking mission.This thesis focuses on manual control rendezvous by use of virtual reality, which is quite different form the traditional research method based on cross drone. Important issues on manual control rendezvous process, such as relative parameter measurement, stereo display, and visual characteristic are discussed. The main work and achievements are summarized as follows:Relative parameters measurements based on TV image is proposed. 1) Imaging model of TV videos is analyzed theoretically and simplified according to its imaging characters during manual control rendezvous, which raises the speed and stabilization of model computing. 2) Procedure for computing parameters of simplified model is presented based on two iterated steps, and simulation experiments show that simplified model is equivalent to integrated model, which can be used to study videos calibration and relative parameter measurement. 3) The method of relative parameter measurement is derived from monocular and binocular videogrammetric system. 4) Recover method of degenerative image is studied and the model of blurred image during manual control rendezvous is proposed. By using anti-filter recover method, we improved the definition of blurred image and increased measurement precision of relative motion parameters.Stereo display is realized and the frequency of stereo scene is optimized. 1) Introducing stereo visual model and double-center projection arithmetic, two ways for generating a pair of stereo images are derived from software practice and virtual stereo scene is fulfilled. 2) Using relativity between frames and closed loop control of scene complexity, frequency of stereo scene is optimized and instability of display frequency is resolved.Strategy of manual control rendezvous based on cross drone is analyzed. Vision error from cross drone image is interpreted theoretically and resolved in practice, which is very important for application in rendezvous and docking project. 1) Manual control rendezvous strategy based on cross drone is discussed in detail and limitation is summarized. 2) Reasons of vision error from cross drone are interpreted and the affection on manual control procedure is analyzed. 3) Making use of stereo scene, vision error is eliminated. Stereo display increases estimation ability of astronauts during rendezvous course, which can reduce fuel consumption and be testified in simulation experiments.Manual control rendezvous simulation system based on virtual reality is constructed with distributed framework. 1) Design method and hierarchy frame of the system are proposed based on theory of oriented-object design and reapplication design pattern, and design projects of subsystems are discussed in detail. 2) In the system, simulation experiments are finished based on cross drone and stereo scene. Experimental results show that astronauts can get more information of relative motion status between spacecrafts in stereo scene, which obviously is beneficial to increasing the success rate of manual rendezvous and docking control.Research on manual rendezvous control based on virtual reality is an innovative work and an instructive attempt in the field of rendezvous and docking technology. The proposed method of thesis is of value in China manned spacecraft project and other space application projections.更多还原