Research On The Visual Alignment Technology And Design On The Control System Of Ultrasonic Dry Cleaning Machine

With the continuous development of liquid crystal display technology,there are more and more kinds of liquid crystal display,and the market demand is increasing.In the production of LCD screens,the cleanliness of the glass substrate and the accuracy of the direction of the grooves are important factors that affect the quality of LCD screens.Therefore,in order to improve the efficiency and yield rate of the LCD screen production line,improve the cleanliness of the surface of the glass substrate and the accuracy of the direction of the grooves,the control system of the ultrasonic dry cleaning machine that clean LCD screen's glass substrate is designed,and the algorithm of edge extraction of alignment marks in the visual alignment system is studied.In order to meet the requirements of cleaning machine in operation,the control system of ultrasonic dry cleaning machine is designed in this thesis.The Mitsubishi Q series PLC is used as the control unit of the equipment.The hardware selection and circuit design of each part of the equipment motion control system are performed,and the corresponding PLC program is designed.In order to meet the real-time requirements of the LCD screen production line for equipment control,the communication network structure of the equipment is designed,and the CC-LINK communication system of the equipment is built.In order to realize the visual alignment of LCD glass substrate after rotation,the structure of the visual alignment system is designed and the corresponding hardware is selected.On the basis of grasping the camera calibration principle,the camera calibration experiment of the visual alignment system is carried out by using zhang zhengyou camera calibration method.The visual alignment detection and analyzes the importance of accurate extraction of edge information of alignment marks are designed in this thesis.Aiming at the feature thatLOG operator is easy to produce false edge when extracting edge of alignment marks,an improved LOG algorithm is proposed in this thesis.It satisfies the value characteristic of the variance parameter of the LOG operator while reducing the value of the operator.By comparing the two algorithms,it verified that the improved LOG algorithm can better meet the system accuracy requirements when extracting edge information of alignment marks.This thesis research results have been applied to the LCD panel production field of ultrasonic dry cleaning machine,through to the records of running status of equipment at the scene of the production,it proves that the equipment movement control system running stable and vision alignment system judges rotation angle accurately.These show that the equipment can meet the practical requirement of LCD panel production line.