视觉物质点跟踪方法在柔索模型验证中的应用

发布时间：2018-04-10 02:31

  本文选题：柔性绳索　切入点：物质点跟踪　出处：《航空学报》2017年12期

【摘要】：空间柔性绳索在航天航空领域有着广泛的应用,柔性绳索具有结构大、刚度低、大变形的特t点,在做大范围运动时位移、转动与弹性变形相互耦合,增大了其动力学建模的难度。为验证柔性绳索动力学模型的准确性,采用非接触式的视觉测量方法进行实验验证,利用背景建模、差分、平滑与二值化一系列图像预处理方法提取绳索目标区域,并基于距离变换的多尺度连通骨架算法计算出绳索中心线,通过求解相机外参数矩阵计算出绳索中心线的平面位置。由于柔索自身灰度均匀,图像特征不明显,无法对绳索上特定位置进行跟踪,现有方法都在测量对象上粘贴或喷涂特征点,对于质量轻、弯曲刚度小的柔索,这种方法会影响柔索自身的动力学特性,因此提出一种适应绳索弯曲及纵向弹性形变的物质点跟踪算法,能够不借助外加特征的情况下,对绳索上任意给定物质点进行跟踪计算。以基于绝对节点坐标方法建立的柔索动力学模型为例验证其模型的准确性,结果表明,该绳索动力学模型仿真结果与实验结果具有较强的一致性。相比于其他测量方法,物质点跟踪算法能够降低柔索测量过程中的外干扰因素,为动力学模型验证提供准确的实验参考结果。
[Abstract]:Space flexible rope is widely used in the aerospace field, with flexible rope structure, low stiffness, large deformation characteristics of T, to expand the scope of movement displacement, rotation and deformation of elastic coupling, increases the difficulty of modeling. In order to verify the accuracy of dynamics of flexible rope model, using the visual measurement the method of non-contact experiments, the use of background modeling, differential, smoothing and binarization of a series of image preprocessing method to extract the rope target area, and based on the multi-scale distance transform connected skeletonization algorithm to calculate the center line of rope, calculated by solving the camera parameter matrix of plane position. Due to the center line of rope cable in their gray uniform, image features are not obvious, not for tracking the specific position of the rope, the existing methods are pasted on the measuring object or spray feature points for light weight, bending Bending stiffness of small cable, this method will affect the dynamic characteristics of the cable, so put forward a rope bending and longitudinal elastic deformation of the material point tracking algorithm, can not by means of external characteristics of the circumstances, for any given material point on the rope track calculation. To verify the accuracy of model as an example the establishment of the absolute nodal coordinate method based on the dynamic model of the cable. The results show that the good consistency between simulation results of the rope kinetic model and experimental results. Compared with other methods, material tracking algorithm can reduce cable interference factors in the measurement process, and provide experimental reference for accurate dynamic model validation.

【作者单位】： 哈尔滨工业大学航天学院;中国空间技术研究院总体部;
【基金】：国家“973”计划(2013CB73004) 国家自然科学基金(11772102)~~
【分类号】：TP391.41;V414
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本文编号：1729283