【作者】 张志勇；

【导师】 朱大勇；

【作者基本信息】 电子科技大学 ， 光学工程， 2008， 博士

【摘要】 光电测量技术具有非接触、精度高等优点，在测量飞行目标的相对位置和姿态的导航系统中具有重要的应用，如舰载直升机助降光电引导系统、航天器空间交会对接过程中的光电导航系统等。而这些应用在系统的测量精度和实时性方面都有较高的要求，因此对于精确、快速的光电测量技术进行研究有重要科学意义和应用价值。本文介绍了直升机助降光电引导系统和航天器空间交会对接光电导航系统中所采用光电测量技术的发展现状、趋势以及基本理论。从理论上和实验上分别对单目视觉的测量技术、双目视觉的测量技术和相位式激光测距技术进行了深入的研究。正交迭代OI(Orthogonal Iteration)算法是一种快速且能全局收敛的单目摄影测量算法。但是使用该算法在近距离对三维目标测量时，距离测量误差较大。本文提出了增加旋转矩阵约束条件的改进方法，建立了共面特征点的共线性方程，得到了一种快速、准确且能全局收敛的位置、姿态测量算法。计算机仿真表明，采用本文改进算法总能得到正确的旋转矩阵，同时也提高了距离测量精度。本文还对拍摄的三维目标真实图像进行了实验研究，使用改进算法测到的相对距离和旋转角的精度都优于OI算法的结果。改进算法对于二维或三维目标位置与姿态测量技术具有重要的理论和实用价值。针对舰载直升机助降光电引导技术，本文建立了一种双摄影测量算法模型，该模型是在目标模板两侧各安装了两台摄像机，分别获取飞行目标两侧特征点的图像，在提取出特征点的图像坐标后，使用线性算法计算出目标相对位置和姿态的初始解，再使用非线性优化算法得到了最优解。在研究双摄影测量算法模型的基础上，建立了一套直升机助降光电引导演示系统。它由两台大功率半导体激光照明装置和两台精密CCD(Charge Coupled Device)摄像机、目标模板以及高性能DSP(Digital Signal Processing)数据处理装置组成。实现了实时图像处理、目标跟踪和位姿参数的测量。进行了室外实验，测量得到目标的相对平移误差小于5cm，偏航角误差小于±3°，其精度与国外直升机光电助降系统ASIST(aircraftship integrated secure and traverse)的技术指标相近。该直升机着舰助降演示系统在国内尚未见报道。本文基于基因遗传算法求解病态矩阵的方法，对国外文献中一种经典的多平面摄像机镜头标定方法进行了改进，该标定方法可以同时利用目标空间和图像空间的特征，能得到较为精确的像机内部参数，但是在模板平面旋转角度较小时，计算结果会出现不稳定。仿真计算表明，采用本文改进方法后得到了更为稳定和准确的像机内部参数。由此求解出反向投影畸变模型下的镜头畸变系数，能够适用于实时测量系统。该方法具有重要的理论和实用价值。为了确定飞行目标位置，本文对传统的相位式激光测距方法进行了改进，提出了一种快速、高精度的相位式激光测距方法。该方法采用内、外光路替代传统机械转换光路的方法，去除了电路中的附加相移，提高了测量速率。使用单片机、复杂可编程逻辑器件进行数据处理与逻辑控制，简化了电路设计，提高了系统的稳定性。进行了室内测量，实验测量速率达到5Hz，测距数据精度3σ小于81．181mm，稳定度3ε小于3．688mm。本文研究的相位式激光测距方法对今后的工程系统研制具有重要的参考意义。更多还原

【Abstract】 Electro-optical measurement technology has the advantage of non-contact and highaccuracy,and it has an important application in the areas of the relative position andpose sensing for a flying object,such as the landing guidance system for a ship-bornehelicopter,and the optical guidance system in the spacecraft rendezvous and docking(RVD) process.These applications have high requirements for the measurementaccuracy and data update rate.Hence,researching on the fast and accurateelectro-optical measurement technology has important scientific significance andapplication value.An overview of the electro-optical measurement technology,the tendency and thefundamental theories are given,which is used in the helicopter’s landing guidancesystem and the navigation system for the spacecraft RVD.An intensive study has beenmaken in theory and experiment on the pose estimation method,which is based on themonocular vision and the dual camera vision respectively,and on the laser range findertechnology,which is based on the phase shift measurement.The Orthogonal Iteration (OI) Algorithm is introduced,which has a fast convergentspeed,but the results have a large translation error in the close range,when using thethree-dimensional feature points.After the rotation matrix solution in the OI algorithmbeing refined,an efficient pose estimation algorithm is derived.Simulation results of theimproved algorithm show that the proper rotation matrix is always obtained,which inturn improves the accuracy of the translation vector.The comparison experiments showthat,when using the improved algorithm,the results of the relative distance and therotational angles are better than those using the OI algorithm.The improved algorithmhas a great theory and application value on the pose estimation system for atwo-dimensional object or a three-dimensional object.A relative position and pose determination algorithm is proposed based on the dualcamera vision,which can be used for the shipboard helicopter landing aid system.Twocameras are set on two sides of the object to acquire the characteristc points’ image;the initial value of the pose of the object can be caluculated using the linear algorithm afterthe pointes coordinates extracted;then the nonlinear algorithm is used to obtain anoptimal solution.Based on the research of binocular vision measurement algorithm,thehelicopter landing aid demonstration system is setup.In this system,two high powersemiconductor laser illuminator devices and two precise CCD (Charge Coupled Device)cameras,a model plane and a high performance DSP signal process device are used.And the real-time image processing,object tracking,and pose estimation are realized.The outside experiments show that,the error of the relative object distance from thecamera is less than 5cm,and the rotational angle error is within±3°.The accuracy ofthe results is close to those of the ASIST (aircraft ship integrated secure and traverse)system.This demonstration system has not been reported in domestic.We use the Genetic Algorithm (GA) to solve the ill-conditioned equations,and awell-known camera calibration method based on the multi-plane is improved.Using themulti-plane calibration algorithm,both the characters of object space and image spaceare used,and accurate intrinsic parameters could be obtained,but the results may beunstable when the rotation angle of the pattern plane is small.Simulation shows thatmore stable and accurate results are obtained after it being improved.The distortioncoefficients under the backward projection model are computed,which can be appliedto a real-time measurement system.This calibration algorithm has important theory andapplication value.To determinate the flying object’s position,we make some improvement on theconventional laser range finder based on the phase-shift measurement,and a fast andhigh accurate laser range finder method based on the phase-shift measurement isproposed.Instead of conventional mechanical switch and single receiving circuit,separate circuits and optical units were designed for the inside and outside beams,usingwhich the appended electornic phase shift is eliminated and the measurement speed isincreased.The Micro-Controller Unit (MCU) and Complex Programmable LogicDevice (CPLD) are used in the data processing and the logical control,which makes thecircuit design easier and improves the measurement stability.The experimental dataaccuracy is 81.181 mm (3σ),stability is 3.688mm (3ε) and data update rate is better than5Hz with the indoor measurements.This method provides an important reference for theengineering research.更多还原