Design Of Automatic Connection Device For Liquid Chlorine Cylinder Filling Pipe Based On Machine Vision

With the rapid development of domestic chemical industry,the utilization rate of liquid chlorine is gradually increased,which makes the filling safety of liquid chlorine cylinders gradually get more attention.Currently,the domestic and foreign researches on the filling of liquid chlorine cylinders are focused on the accurate control of cylinder filling volume and the traceability of cylinder information in the filling process,and the connection between the filling pipe of the charging device and the cylinder valve is completed manually.In the pipeline connection operation,if there is chlorine leakage,it will pose a great threat to the safety of filling workers.To solve this problem,this topic designs an automatic connection device of filling pipe combined with machine vision to replace manual operation,which can effectively improve the safety and filling efficiency in the filling process of liquid chlorine cylinder,and make the filling process more intelligent and automatic.According to the operating environment and actual needs of automatic filling of liquid chlorine steel cylinders,an automatic connection device for filling pipelines is designed.Including cylinder clamping,valve port clamping,valve opening and closing,outer ring feeding and rotation,binocular camera clamping and chlorine gas detection alarm and other devices,and the strength analysis of key components in the device is carried out to ensure the reliable work of the device.On the basis of the camera imaging model,the coordinate systems of the camera and the transformation relationship between the coordinate systems are determined,and the calibration experiment of the binocular camera used in the vision system was completed by Zhang zhengyou’s camera calibration method,and the internal and external parameters and distortion coefficients of the camera were obtained.In order to solve the valve port location problem of liquid chlorine cylinders,a valve port identification and location algorithm is proposed,which combines YOLOv4 target detection algorithm and ellipse detection algorithm based on arc extraction.After the location frame of liquid chlorine cylinder valve port was obtained by YOLOv4,the valve port image in the location frame was intercepted for ellipse detection,and the detection ellipse in the images of the left and right cameras was matched and screened to determine the correct valve port fitting ellipse.The ellipse detection algorithm adopts the double-threshold method to filter the arc segments,obtains five key ellipse parameters through the ellipse parameter calculation formula,and formulate three-tuple screening conditions and fitting ellipse scoring rules to make the fitting ellipse of the valve port and the coordinates of the center point more accurate,and obtain the three-dimensional coordinates of the center point of the cylinder valve port through three-dimensional reconstruction.An experimental platform for valve port location of liquid chlorine steel cylinder is built to verify the effectiveness of the identification and location algorithm.Finally,the overall control scheme and electrical principle of the automatic connection device for filling pipelines are designed,the selection of controllers,drivers,sensors and other devices is completed,and it is determined that the control system adopts visual feedback control and PID control.The PID control system simulation experiment is completed through Simulink.