Research On Speckle Two Dimensional Velocity Measurement By Using The FPGA

The main content of the thesis is to use FPGA to measure the moving speed of featureless objects.As for the selection of the featureless objects,hot-rolled steel is selected as the treatment object.The design scheme of this paper is to use laser to irradiate the surface of hot rolled steel to form speckles,and determine the moving position of hot rolled steel by matching the moving position of the speckles on the surface of hot rolled steel,so as to further calculate the moving speed of hot rolled steel in the two-dimensional plane.Image matching is used to match the speckle position of two images in the video stream,and the moving position of hot rolling steel is obtained by obtaining the moving position of speckle.Compared with the use of computer software,using FPGA can get faster results.The design tool used in the thesis is Quartus ? produced by Intel company,and Singal Tap software is used to verify the data of each structure.Choose altera ep4ce10 type FPGA chip,,transfer the acquired image to FPGA via Ethernet,cache the acquired data through SDRAM,read the video data in SDRAM,select two frames of images for matching,and match The data is transmitted to the host computer via Ethernet.In the selection of image matching algorithm,the absolute error sum algorithm based on gray value(SAD method)is used for matching calculation.For the selection of the feature region in image matching,the verification was done by using MATLAB to establish a three-dimensional coordinate map,and finally the matrix template region of 24×24 pixels was selected as the feature region of image matching.The matched image information is packaged and transmitted to the host computer through the UDP protocol of 100 M Ethernet,and the matched video stream is displayed through VGA.By collecting the image information of speckles on the surface of the hot-rolled steel moving at a constant speed,and observing the image data of the upper computer after the matching operation,the moving speed of the speckles is calculated,and then the moving speed of the hot-rolled steel is obtained.After multiple measurements and calculations,comparing the matching results of the median filter and the unfiltered image,the two-dimensional moving speed of the hot-rolled steel is obtained.The required matching time is 11.24 ms,which achieves the experimental goal.