小、暗、多、快目标的近距离测量关键技术研究

	小、暗、多、快目标的近距离测量关键技术研究
	吕耀文
学位类型	博士
导师	王建立
	2014-07
学位授予单位	中国科学院大学
学位专业	机械电子工程
摘要	现代靶场为适应武器系统快速发展的需要，提出了对小、暗、多、快目标测量的新要求。由于目标具有小、多、不发光和速度快等特点，要获取目标的清晰图像，相应的光学测量设备必须具有高帧频、高灵敏度和大视场的特性。基于对成本和安全性的要求，光学测量设备的布站位置距目标相对较远，因此无法给出对小、暗、多、快目标作用过程的细节。本文结合现代电子通信技术与摄像测量方法从低成本高速CMOS摄像机设计、图像采集存储、摄像机标定和目标测量等关键技术对该问题进行了深入的研究。本文的研究内容主要集中在以下几个方面：（1）根据测量要求并考虑研制成本，本文设计了一款分辨率为2K×1K、最高帧频为280帧、曝光可调的低成本高速CMOS摄像机，并详细说明了高速摄像机设计中的关键技术，尤其对高速数据采集中的位对齐和字对齐技术做了重点论述。为了适应测量设备小型化、便携化和低功耗的发展趋势，本文设计了一套基于高速SATA传输接口的嵌入式图像存储系统。实验结果表明，该图像存储系统最高图像存储速度可以达到294MB/s。（2）摄像机标定算法在本文中做了详细讨论和深入研究。以平面棋盘为标定工具，采用平面标定算法标定测量系统摄像机的内外参数，并针对该算法在实际标定中标定结果不收敛的问题，在随机抽样一致性（RANSAC）算法的基础上，提出了一种改进的标定算法。实验结果表明，改进的标定算法与传统方法相比，在降低算法迭代次数，优化算法运行效率的同时，标定精度提高了35%。（3）根据小、暗、多、快目标测量的实际需求，本文采用平面摄像测量方法单目测量目标的脱靶量和落点坐标，该方法具有测量简便、灵活性高的优点。在此基础上，针对点目标抛物线运动测量的问题，证明了二次抛物线的射影几何性质，并提出了一种针对抛物线运动目标三维信息测量的单目测量方法。通过仿真和实际小球投掷实验，验证了方法的正确性和可行性。该方法与双目测量结果比较，小球三维坐标测量误差在1.2%以内。（4）针对更一般的交汇测量任务，本文首先详细介绍了交汇测量中的关键技术，包括三维欧式重构、立体匹配与外参数标定等；其次，重点分析了外参数对测量精度的影响，通过仿真得到了最优的结构参数；最后，针对小、暗、多、快目标的落点测量问题，提出了一种无需标定的平面交汇测量方法，该方法可以应用于大范围、远距离、粗测量的场合。
其他摘要	With the rapid development of weapons systems, new requirements are raised for measurement of small, dark, rapid, multi targets in modern shooting ranges. Since the rapid, multi targets are small and non-luminous, to get clear pictures of the targets, corresponding optical measurement equipment must have the characteristics of high frame rate, high sensitivity and large field of view. For reasons of safety and cost, optical measurement equipment are posited far from the targets, therefore details of the targets movement are missed. Based on modern electronic communication technology and camera measurement technique, image acquisition and storage, camera calibration and targets measurement are taken into consideration this problem in this dissertation. The main works are summed in follows: (1) A new low-cost high speed camera is designed with the consideration of measurement requirements and hardware costs. The image resolution is 2Kx1K and the maximum frame frequency is up to 280 fps under the condition of full resolution. Exposure of the camera can adjust to application environment. The key technologies of camera design are explained in details, especially for bit alignment and word alignment technique in the process of high-speed data acquisition. Under the miniaturization of the measuring device, trend of better portability and low power consumption, an embedded image storage system is also designed with the high-speed SATA interface. The experimental results indicate that the bandwidth of storage system can reach 294MB/s。 (2) In this paper, the camera calibration technology is in-depth researched. The external and internal parameters of camera are estimated using the plane calibration algorithm with planar checkerboard. The plane calibration algorithm is easy and flexible, but sometimes the algorithm is not convergent in practice when the number of calibration images more than 10. A modified method is proposed to ensure calibration convergence. The modified method divides the calibration images into correct images and false images using Random Sample Consensus（RANSAC）algorithm, and calibrates camera only for good images. The experimental results show that the robust modified method can reduce the number of iteration, and calibration precision increase by 35%. (3) To satisfy actual demand for the measurement of small, dark, rapid, multi targets, planar imaging measurement, easy and high flexibly, is used to monocular measure the miss distance and drop point coordinates of targets in this paper. On this basis, nature of the projective geometry of parabola is proved and a novel monocular measurement method is proposed for parabolic motion of point targets. Both computer simulation and real data have been used to verify the feasibility of this method. . Practical globule throwing experiments show that the measurement error is less than 1.2% compared with binocular measurement methods. (4) For general measurement tasks, the key technologies for intersection measuring are firstly introduced, which include 3D European reconstruction, stereo matching and external parameters calibration, etc. Secondly, the influence of external structure parameters on the accuracy of measurement is analyzed emphatically, and the optimal parameters are achieved by numerical simulation. Finally, Aiming at measurement of the small, dark, rapid, multi targets drop point, a novel plane intersection method is raised and it can be applied in large view field, long distance and coarse measurement occasions.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41450
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	吕耀文. 小、暗、多、快目标的近距离测量关键技术研究[D]. 中国科学院大学,2014.

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