相似材料模型监测的光学图像法研究

Optical image method to deformation monitoring of similar material model

针对传统相似材料模型观测方法中存在的监测装置昂贵、监测时间间隔长、工作量大等缺点,结合透镜投点、近景摄影测量以及图像识别技术,提出了一种用于模型变形监测的光学图像法.该方法利用透镜放大成像的原理将模型监测点微小位移放大投影到屏幕上,通过相机获取不同时刻的投影图像,结合图像识别方法准确提取图像中控制点和投影点的中心坐标,再采用二维直接线性变换解算投影点的物方平面坐标,进而获取精确的模型变形值.结果表明:光学图像法测量模型点的位置精度为0.1mm左右,监测点的位移精度高于0.01mm,所测得的下沉与水平移动曲线均与实际情况一致.与其他模型监测方法相比,该方法具有监测时间间隔短、精度高的优点,可以获取小时间尺度下模型变形的细节特征,为全面研究动态沉陷规律提供了一种新的监测手段.

For the disadvantages of the traditional similar material model observation method,such as expensive monitoring device,long monitoring interval,and large amount of work,etc.,the paper proposed an optical image method to monitor the deformation of similar material model combining with convex lens projection,close-range photogrammetry and image recognition technology.In this method,the convex lenses are used to amplify the micro displacement of the monitoring points projected onto the screen,and the projected images at different time are captured automatically by a camera,and the center coordinates of control and projected points in images can be extracted based on image recognition method.Then the plane coordinates of projected point in the object space can be calculated by 2Ddirect linear transform,and the accarate displacement of the monitoring points to the model can be calculated by the lens’ magnification.The results show that the position accuracy of the model monitoring points measured by optical image method is about 0.1mm,the displacement accuracy of the monitoring point is higher than 0.01 mm,and the measuring subsidence and horizontal movementcurves are both consistent to actual conditions.The optical image method has the advantages of short monitoring interval and high accuracy compared with other model monitoring methods,so that it can obtain the detailed deformation characteristics of similar material model on smalltime scale,thus,providing a new monitoring method to comprehensively study the characteristics of dynamic mining subsidence.