【作者】 吴秋爽；

【导师】 刘荣强；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 硕士

【摘要】 随着太空探索、对地观测、军事侦察和海洋勘探等空间活动的迅猛发展以及未来复杂太空任务的需求,对超大尺度、超高精度、超大刚度、超轻型结构的空间伸展臂的需求越来越迫切。由于受到航天运载工具的运载空间的限制,要求空间伸展臂在发射阶段必须折叠起来收藏于整流罩内,待航天器进入轨道后,再靠自带的动力源将其展开至工作状态,这就要求空间伸展臂展开后具有更高的重复展开精度和定位精度。如何对大尺寸、高精度伸展臂展开后的精度进行测量,已成为未来伸展臂研制、测试亟待解决的问题。本文在分析索杆铰接式伸展臂展收原理及结构特点的基础上,提出了索杆铰接式伸展臂的直线度误差以及展开后横向框架的端部扭转角度,水平、竖直偏移量的激光准直测量方法。根据激光准直测量的工作原理,对索杆铰接式伸展臂激光准直测量系统进行了设计。运用所设计的激光准直测量系统对伸展臂横向框架相应节点的空间坐标位置进行了测试,通过计算得到伸展臂的直线度误差和各跨展开单元的扭转角度和偏移精度。对激光准直测量系统的光源进行分析与比较,根据激光器光源的输出特性,选取外腔式氦氖激光器作为测量系统的光源并设计了激光器固定支架。选择四象限探测器接收激光束,并对四象限探测器的工作原理及性能进行了分析。对影响四象限探测器的因素进行分析,影响因素包括光束漂移、光斑大小以及背景光等因素。根据四象限探测器输出信号特点,设计了四象限探测器输出信号运算电路、放大电路以及数据采集电路并开发了索杆铰接式伸展臂激光准直测量系统的测量软件。根据激光束扩束原理,提出了激光器扩束的具体方法以及光束垂直性和准直性调节的方法。设计了二维标定台对四象限探测器进行平面标定,确定标定平面内的标定点的实际位移值和相对应的电压值,通过插值计算确定了平面内非标定点的实际位移值电压值的近似关系,校正了由于四象限探测器的不均匀性带来的误差,提高了四象限探测器的测量范围。在实验室条件下进行了激光光源输出稳定性、光斑能量中心的一致性、四象限探测器线性度以及平面标定等实验,对伸展臂缩比样机的直线度误差和位置误差进行测量并分析了产生误差的原因。更多还原

【Abstract】 With rapid development of space exploration, earth observation,military reconnaissance,marine explorationand requirement of future complicated space mission, there is an urgent need to space deployable masts of extra large scale, ultrahigh precision, ultrahigh stiffness and ultra-lightweight structure. Because of the space restriction of astronautics carrier, it requests the space stretchable arm must be folded in the cowling in the launching phase, and launches to an active status by power from its own power supply after it reaches planed orbit, which need a higher position precision after the extension. How to measure the position precisely has become a future key point on studying stretchable arms.This paper basing on the analysis of extension and folding of rope hinge stretchable arm, raised the concrete solutions for the main measuring accuracy, straight line error of rope hinge stretchable arms, and the reverse angle, horizontal and vertical displacement of crosswise frame nose after it is launched. According to the principle of laser alignment measurement, proposed the rope hinge stretchable arm laser alignment measuring plan. The straight line and position error of the stretchable arm is obtained indirectly according to the space coordinates position of the crosswise frame corresponding points, which is measured by the laser system.By analyzing the light source of the laser measurement system, according to the characteristics of the laser light source, the proper laser devices are chosen as the light source and the laser fixation is also designed. The right laser beam photoelectric detector is chosen, and the principle and performance of four-quadrant laser detector is analyzed. After analyzing the factors affecting the four-quadrant detector, some factors like the beam drifting, spot size and background light are found. According to the output signal characteristics of the four-quadrant detector, the output signal processing circuit, amplification and filter circuit of the four-quadrant detector are designed. Beyond these, a data acquisition and processing control box is made and the real-time measurement software is developed for the stretchable arm laser autocollimator system.According to the principle of the laser beam expanding, the specific methods for laser beam expanding and adjustment to verticality and alignment of the laser beam. Because of the limitation of one-dimensional calibration, a two-dimensional calibration set is designed to make plane calibration for the four-quadrant detector. The set can determine the actual displacement and corresponding voltage value of the standard fixed-point in the calibration plane. The approximate relationship of the actual voltage value is determined by the interpolation of non-calibration points in the plane, and the error which comes from the uneven character of the four-quadrant detector is also corrected. Several experiments are taken out under the laboratory condition, including the stability of laser light output, the consistency of the spot energy center, linearity of the four-quadrant detector and plane calibration experiments. The straightness and position error of the minified model machine is measured and the cause is analyzed.更多还原