Digital image correlation based high-speed crack tip locating method and its application

Based on a digital image correlation (DIC) method with the measurements of a high speed crack''s displacement and strain fields, a technique to accurately and automatically locate its crack tip has been developed. The crack tip is identified by finding the abrupt jump on the opening (or dislocation) curve of a point on the trace of the crack propagation, while the opening is measured through a virtual extensometer technique and the abrupt jump is identified by finding the peak on the curve. The method was verified using a specially designed experiment and applied to measure the critical crack tip opening angle of a rock sample. Because the involvement of analytical models has been avoided and then the good performance could be ensured for low resolution speckle images, this technique is expected to be very useful in the quantitative study of high speed cracks in experiments using high speed cameras.     

岩石破坏动态变形场观测系统及应用

基于高速图像采集设备和数字散斑相关方法（DSCM）,建立了一套岩石破坏动态变形场观测实验系统,介绍了系统的组成和原理,重点阐述了用于岩石动态变形测量时光源的选择、采集速率的设置和图像采集的触发等关键技术。用此动态变形场观测实验系统可完成动（静）态载荷作用下岩石破坏瞬间试件表面图像的准确高速采集,并进一步完成变形场的定量分析。用设计的系统完成了岩石巴西圆盘实验和岩石I型裂纹动态断裂实验,对动态变形场观测实验系统的可行性和有效性进行了验证。观测系统获得的脆性岩石失稳破坏过程中动态、定量的变形场数据可为深入研究岩石失稳破坏机理提供基础的数据和认识。     

基于模糊控制的无线自动泊车系统关

为降低泊车操作的难度,减少因泊车引发的事故,以LABVIEW为开发平台,运用现代图像处理技术、无线通信技术及模糊控制理论设计了自动泊车系统.介绍了用图像处理技术获得汽车的位置信息及方向信息的方法,详细阐述了运用模糊控制理论设计自动泊车控制器的过程,以及用单片机MSP430F149及无线收发芯片nRF905搭建无线通信模...