A direct communication system between xHC(extensible host controller) and FPGA is proposed to solve the transfer and storage issues of high resolution and high frame camera array via PCI Express.The image data could be transferred into processing and storage unit without passing host memory through PCIE peer-topeer data transmission,which greatly simplifies the physical path of data transmission,reduced the data transmission latency and avoided the negative influences of the operating system as well.A PCIE interface was designed to implement the communication between xHC and FPGA based on hard PCIE core.The control and driver task of xHC and the multiple USB cameras that connected to the xHC were completed by FPGA,it could realize the acquisition and transfer of multiple cameras' data.The composite analysis and verification were conducted through dedicated monitor module and Chipscope tool.The result indicates that the system greatly improves the image transmission speed and has strong expansibility.

This paper reports the important research progress in digital image correlation (DIC) method,which is achieved by author and his research group affiliated to Institute of Mechanics at Southeast University.The main progress as follows:(1) Through theoretical error analysis of inverse compositional Gauss-Newton (IC-GN) algorithm in DIC method,a new theoretical error formula was proposed,which further proves the comprehensive advantages of inverse compositional Gauss-Newton algorithm in improvement of computation speed and measurement accuracy;(2) Adopting new theoretical error formula,the optimization and fabrication method of digital speckle pattern was developed to ensure the consistency and accuracy of measured results.(3) Based on camera array and image stitching technology,a super-resolution digital image correlation method was developed,which greatly improves strain measurement resolution of DIC.(4) A calibration method of 3-D system with large field of view was proposed,which can realize real-time calibration of a 3-D measurement system external reference and automatic correction of camera position and orientation in a multi-camera measurement system;(5) A portable in situ 3-D measuring instrument and a multi-scale DIC measurement system were developed and real-time 3D digital image correlation was realized,which further meet the application requirements of DIC method in industrial online detection and medical field.