面向航天器在轨对接的微距激光测距传感器的研究

发布时间：2018-03-10 22:06

本文选题：激光测距传感器　切入点：CCD像元细分算法　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：航天技术不断发展,人类在太空中的活动越来越多,有大量太空任务需要完成,例如空间设备的维护和废弃卫星的捕获等。由空间机械臂代替宇航员完成空间任务,已经成为航天工程研究的热点。空间机械臂准确完成任务的前提是能够实时、精确地检测目标的位置,当机械臂距离任务目标较远时,可以采用雷达、视觉等传感方式对目标位置进行检测,而当距离特别近时,这些测量方法的精度和稳定性是有限的。本文对近距离激光测距传感器进行研究,研制出一款高精度、高集成度的近距离实时测距传感器,并对之进行了性能分析及实验研究。首先,本文从光学系统和电气系统两部分对激光测距传感器进行了分析及设计。针对光学系统,结合任务要求,对光路及光学元件进行了选择,同时对光学系统进行分析,提出了用于光学系统参数优选的指标,对光学系统参数进行设计。针对电气系统,综合分析各种控制器的特点,本文以FPGA作为传感器的主控制器,用VHDL硬件语言对传感器各模块进行设计,实现了部分软件功能的硬件化。其次,本文对CCD像元细分算法进行研究并提出算法评价模型。为提高光斑中心的定位精度,提高传感器的测量精度,搭建用于像元中心定位的Labview实时工作平台,对多种像元细分算法进行分析验证;为选择最适于本传感器系统的像元细分算法,建立用于像元细分算法优劣判定的层次分析模型,并利用该模型,针对本文研制的传感器,对二分法等四种像元细分算法进行评价。然后,对本文研制的传感器的标定方法进行理论及实验研究。针对总装完成的传感器,为减小加工和安装等系统误差对测量结果的影响,本文对传感器的标定方法进行了理论和实验研究,并对标定结果进行了组内和组间检验,根据实验结果,选择分段多项式最小二乘拟合的标定方法作为最终的标定方法。最后,提出了一种利用三点距离来检测平面位姿的算法。应用本文设计的激光测距传感器,对近距离的某一平面进行了位姿检测实验。实验结果表明,本文研制的激光测距传感器能够实时、高精度地完成近距离的位姿检测任务,满足机械臂末端对距离测量的要求。
[Abstract]:With the development of space technology, more and more human activities in space, there are a large number of space missions to be completed, such as the maintenance of space equipment and the capture of abandoned satellites. Space manipulator can detect the position of the target in real time and accurately. When the robot arm is far away from the target, radar can be used. Vision and other sensing methods detect the position of the target, but when the distance is very close, the accuracy and stability of these methods are limited. In this paper, a high precision laser ranging sensor is developed. The high integration real-time ranging sensor is analyzed and experimentally studied. Firstly, the laser ranging sensor is analyzed and designed from two parts: optical system and electrical system. According to the task requirements, the optical path and optical elements are selected. At the same time, the optical system is analyzed. The parameters of the optical system are selected and the parameters of the optical system are designed. Synthetically analyzing the characteristics of various kinds of controllers, this paper takes FPGA as the main controller of the sensor, designs each module of the sensor with the VHDL hardware language, and realizes the hardware of some software functions. Secondly, In this paper, the CCD pixel subdivision algorithm is studied and the algorithm evaluation model is put forward. In order to improve the location accuracy of spot center and the measurement precision of sensor, the real-time working platform of Labview for pixel center location is built. In order to select the most suitable pixel subdivision algorithm for the sensor system, a hierarchical analysis model is established for judging the advantages and disadvantages of the pixel subdivision algorithm. Four pixel subdivision algorithms, such as dichotomy, are evaluated. Then, the calibration method of sensor developed in this paper is studied theoretically and experimentally. In order to reduce the influence of system errors such as machining and installation on the measurement results, the calibration method of the sensor is studied theoretically and experimentally, and the calibration results are tested within and between groups, according to the experimental results. The calibration method of piecewise polynomial least square fitting is selected as the final calibration method. Finally, an algorithm using three-point distance to detect plane position and pose is proposed. The experimental results show that the laser ranging sensor developed in this paper can complete the task of position and attitude detection in real time and high precision, and meet the requirements of distance measurement at the end of the manipulator.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V526;V441

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