Research On Modelica Based Modeling And Simulation Method Of PCBAOI System

The production process of printed circuit board(PCB) has been developed quite mature now and the capabilities of detecting the defect of PCB circuit become the key factor in PCB production efficiency. Automatic optical inspection technology(AOI) is widely used in defect detection for PCB manufacturing. PCB AOI equipment is a complex set of electro-mechanical systems which includes machinery, electronics, optics, control and other subsystems. Being coupled within multi-field is its salient feature. Currently, the domestic research for PCB AOI, affected by various factors, remained at a relatively early level. And the complex electromechanical system with multi-fields coupling are mostly limited to be researched in a various single mutual field because of the less of the knowledge in the impact created by the coupling subsystems.In this paper, the use of modeling and simulation methods based on Modelica modeling language is referred to solve the PCB AOI modeling and simulation problems, which are caused by the unified multi-fields coupling in the complex electromechanical systems. What’s more, a model library of PCB AOI subsystems has been established. It is a new PCB AOI modeling and simulation method, which can be used in the dynamic performance optimization of machinery, control, electrical, visual and other modules for coupled systems on the level of the system. First, the design of PCB AOI system and the evaluation system for image quality are deeply described in order to make the modeling & simulation objective and the evaluation methods of optimization detailed. Secondly, by studying the methods of the modeling and simulation of PCB AOI motion system and imaging system, the simulation model of motion system and imaging system is established. The unified modeling language named of Modelica is used in establishing the structure and drive model, the control system model, light model, focusing system model, the imaging system model on the same platform in order that each model associated with image quality of PCB AOI can form an organic unity of integration. Finally, by analyzing and testing the image quality of PCB AOI systems, influences of the velocity and light illumination disturbance on image quality are studied. At the same time, the clarity indicator of PCB AOI image has been optimized.Results of simulation and optimization experiments show that the PCB AOI system model established by the methods based on the unified modeling language Modelica modeling and simulation can actually has a relatively good expression correspondence with the equipment. It can not only contribute a very good guidance on the optimization of the existing PCB AOI equipment performance, but also supply a good simulation platform for the design and development of PCB AOI equipment.