The Broadband Communications Test PCB Positioning System Based On Machine Vision

With the rapid development of electronic technology,especially in a revolutionary era of broadband communications,signal frequency is higher and higher,it brings higher requirement for the highly integrated and wiring dense communication PCB(printed circuit board)detection.At present,majority of broadband communication PCB complete detection through searching and touching the testing points under the magnification glass.However,this traditional testing methods has many disadvantage such as low efficiency,high labor costs,and a long time stare on the magnification glass will make people's eyes products pain and dizziness,what's worse,it will cause irreversible visual impairment.In allusion to the problems mentioned above,this paper applies the machine vision detection technology to the Mark points location on the broadband communication PCB,and realizes the non-contact real-time detection.In this process,the following studies work are made:1.In order to get high quality digital images,the method of camera installation,lighting,image acquisition and display are researched and analysis according to the image principle of the camera.Determine the structure and work processes of the whole visual positioning system,and choose to Zynq-7000 series chip as the core of Zedboard development board as hardware platform,providing the necessary conditions for the image feature extraction.2.In order to achieve the embedded software development and design of the vision system,the embedded software development environment has been built by fully studying the technical documentation of Zynq-7000.The program for the CPU0 and CPU1 have been designed in the tool of the SDK provided by Xilinx.And developmental the human-computer interaction interface.3.Aiming at acquiring accurate position coordinates of detecting points on the broadband communication PCB,using the position the mark-points on four corners on the board and the relationships between the detecting points and mark-points to realize the it.In digital image processing,the methods of crude-fine template and Rotating Calipers algorithm were used to get the mark-point's characteristic value.It's reduces the amount of computations.4.The experimental results demonstrate that the repeatability of can meet the requirements of the broadband communications test board positioning system based on machine vision.