The AOI Motion Control System Research And Design For Flexible Printed Circuit Board

With the advent of the Information Age,the demand of FPC is greatly improved,so more and more AOI equipment applied to the production line.However,the AOI industry in our country were slow in starting,most of the existing equipment applied only to PCB detection,and the speed and accuracy cannot meet production need.In this context,studied and designed this AOI motion control system for FPC.With the Galil motion controller at the core of the system,and the servo drivers driving the precision modules,the camera can move in a plane fleetly and precisely,thereby to collect the image of the board under test.For the purposes of shortening detection time,introduced arithmetic of mobile camera path planning:using the modified Iterative Selforganizing Data Analysis(ISODATA),to divide class for all of the welding spot on the circuit board,and to abtain the least number of classes after many iterations;Therefrom,it transformed into a Travelling Salesman Problem(TSP),getting the best path by using the Genetic Algorithm(GA).The system adopts the sampling double closed loop to compensate the space.Among this,the theory of precision of the rotary encoder is 10000cts/rev,which driving the motor to the given position.The grating ruler whose resolution ratio is 1?m was used to read the position of the load.The controller moved to a new position after calculating the position error.In addition to this,the system used C#to programme PC,and stored information of the under testing board in the SQL Server data base.We can make some additions and deletions after getting administrator privileges.PC downloaded the result of path planning runned by the MATLAB to the motion controller.Through the UI interface,it achieved the control of the working stand and the real-time monitoring of data.By using different norms of circuit boards,the efficiency and accuracy and practicability of the system were verified.Compared to the traditional order taking images,the path planning algorithm reduced number of pictures and shortened the moving path of camera and reduced the difficulty of image processing,so the work efficiency of AOI device was significantly increased.The advanced hardware support along with control theory such as double closed-loop,linear interpolation,"S" curve smoothing process made system having the advantages of stable performance and reliable operation.Its repeat positioning accuracy was as high as ±0.02mm,completely reached the level of demand in AOI technology.