基于数字散斑相关方法的矿山相似模拟位移监测

Ming similar simulation displacement monitoring method based on digital speckle correlation

为解决传统采矿相似模拟观测方法存在的自动化程度低、试验前安装过程麻烦、工作量大、精度低等缺点,提出一种适用于采矿相似模拟模型的数字散斑相关方法(digital speckle correlation method,DSCM),实现对相似模拟模型位移场的自动监测。该方法考虑模型沉陷位移规律,将有限元思想应用于模型位移监测,并根据位移特点将模型表面进行分区处理,设计搜索区域以及改进有限元方法以求取位移初值。在此基础上,根据位移矢量大小选用不同的搜索方法,得到整像素级位移精确值,接着使用灰度插值法求取亚像素级位移精确值。最后通过单应变换将不同时期的监测点像素坐标映射到物方平面得到监测点物方位移。试验结果表明:利用该方法所测监测点的像方分辨率为0.01像素,物方分辨率高于0.001 m,所得位移场的竖直与水平位移与实际情况一致,可以满足矿山岩层相似模拟试验的要求。

Digital speckle correlation method(DSCM) suitable for mining similar simulation model is proposed to realize automatic monitoring of the displacement field of similar simulation model in order to solve the shortcomings of the traditional mining similar simulation observation method, such as low automation,troublesome installation process before test, large workload and poor accuracy. In this method, considering the displacement law of model subsidence, the finite element method is applied to the model displacement monitoring, and the model surface is partitioned according to the displacement characteristics, the search area is designed and the finite element method is improved to obtain the initial value of displacement. Then,according to the displacement vector size, different search methods are selected to obtain the precision value of the whole pixel displacement, the gray interpolation method is used to obtain the precision value of the pixel displacement. Finally, the pixel coordinates of the monitoring points in different periods are mapped to the object plane by homograph transformation to obtain the object displacement of the monitoring points.Experimental results show that the image square accuracy of the monitoring point measured by this method is0.01 pixels and the object square accuracy is higher than 0.001 5 m, The vertical and horizontal displacement of the displacement field is consistent with the actual situation, which can meet the requirements of similar simulation test of mine rock strata.