具有复杂边界条件的拉索索力机器视觉识别方法
Machine vision method for cable force identification in complex boundary conditions
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摘要: 为准确识别具有复杂边界条件的拉索索力,提出了基于机器视觉和广义回归神经网络(generalized regression neural network,GRNN)的索力识别方法。采用基于相位的运动放大算法和亚像素边缘定位等机器视觉技术,通过拉索振动视频提取振动位移时程并识别频率,实现拉索振动变形的多点非接触同步测量;利用有限差分法生成样本数据集,通过麻雀搜索算法(sparrow search algorithm,SSA)寻找GRNN最优光滑因子,构建SSA-GRNN索力识别模型以建立复杂边界条件下频率与索力的对应关系,将获取的频率信息输入模型中进行索力识别。以单根拉索为例,开展了复杂边界下拉索的数值模拟和人工激励状况下的拉索试验。结果表明,基于机器视觉和GRNN的索力识别方法可以通过振动视频准确识别频率,提高了对具有复杂边界条件的拉索索力的识别精度。Abstract: In order to accurately identify cable force in complex boundary conditions, a new method of cable force identification using machine vision and generalized regression neural network (GRNN) is proposed. Machine vision technologies, such as the phase-based motion amplification algorithm and sub-pixel edge detection algorithm, are used to extract the vibration displacement time history data and identify the frequency through the cable vibration video to realize multi-point non-contact synchronous measurement of cable vibration deformation. A sample dataset is generated using the finite difference method. The smoothing factor of GRNN is obtained by the sparrow search algorithm (SSA), and a SSA-GRNN cable force prediction model is constructed, establishing the correspondence between frequencies and cable force under complex boundary conditions. The obtained frequency information is input into the model for cable force recognition. Taking a single cable as an example, the numerical simulation of the cable in complex boundary conditions and the cable test under artificial excitation condition are carried out. The results show that the cable force identification using machine vision and GRNN can accurately identify frequencies through vibration video, and improve the recognition accuracy of the cable force in complex boundary conditions.