Research And Development Of The Flexible Circuit Board Intelligent Alignment Device

With the rapid development of intelligent electronic productsand equipment in recent years,the application of the flexible printed circuit board(FPC)is more and more extensive.In the production process of the flexible printed circuit board,alignment is the key technology.In this thesis,the requirement of automatic alignment is studied deeply.Then,an intelligent alignment device based on machine vision is developed,including mechanical,motion control and vision system.A lot of experiments have been carried out on the developed device,and the accuracy,speed and stability of the device have been analyzed and verified.The results of the research are as follows:(1)Aiming at the characteristics of FPC,the intelligent alignment system is designed,,including the mechanical system,control system,vision system.And then,the three coordinate platform based on servo motor and stepping motor is designed;In order to reduce the mechanical damage to the FPC,a vacuum adsorption device is designed for the FPC's soft and thin characteristics.At the same time,the control system uses the motion control card to control the motor,and completes a series of alignment actions with high efficiency and accuracy for FPC.Subsequently,the vision system is studied in detail,then according to the technical index and the internal and external environment of the device,the camera,lens and light source are selected.(2)Then,analyze the advantages and disadvantages of each kind of preprocessing algorithm.The median filtering is used for smoothing denoising,the iterative method is used to segment the region,and the morphological operation is adopted to denoise,finally,edge detection is performed using Canny operator.(3)In the algorithm of image localization,due to the Hough circle fitting is not accurate,single circle fitting random error is larger,and according to the characteristics of FPC positioning circle,in the different radius region,the ellipse is fit and positioned at the same time with the least squares method,and the average value is taken to improve the stability and precision of positioning circle positioning.In the FPC offset angle localization,using the cumulative probability Hough detection line,not only high efficiency,but also can directly detect the endpoint coordinates,easy to calculate the FPC offset angle.(4)The intelligent software system of the flexible circuit board is designed.The Sapera LT software library and the OpenCV function library are used to collect and process the images.In the motion control,the timers in the API function are used.At the same time,set the relevant movement of different signs,through the timer scan status flag changes to determine the implementation of the steps to ensure the stability of the orderly implementation of the system.A large number of experimental verification shows that the system position error does not exceed: ± 0.06 mm,the angle error does not exceed 0.0016 rad,the speed is 3s/chip;...