Design Of Automatic Disassembly Device For Screws Of Wastate Mobile Phones Based On Machine Vision

Used mobile phones often contain many kinds of precious metal materials.With the increasing number of waste mobile phones,recycling and dismantling has become an important way to deal with waste mobile phones.As one of the common fasteners,screws are an important form of connection between various components in mobile phones,and they are also the longest time-consuming link in the disassembly process of the whole machine.The traditional screw disassembly process is almost impossible to be separated from human labor.Problems such as original disassembly means and relatively backward equipment have limited the efficiency of disassembly to a large extent.In order to solve the above problems,this thesis mainly designed and developed a set of automatic disassembly device for used mobile phone screws based on machine vision,and the key technologies were studied.Main works of the thesis are as follows:(1)In this thesis,the process principle and technical requirements of the screw automatic disassembly device are studied.And from this,structure of the device and control system plan based on modular design ideas was formulated.The disassembly module and clamping module are designed based on Solid Works software.At the same time,the design of the control system was completed and the hardware of each module was selected.The design scheme of dismantling equipment for the whole machine of used mobile phones is proposed,and the relationship between the screw automatic dismantling device and the dismantling equipment of the whole machine is clarified.(2)Analyzed the vision requirements of the screw automatic disassembly device,and chose MV-GED500C-T industrial camera,CC085 M lens and ring light source to form the vision system hardware.The nonlinear distortion model and pinhole imaging principle are explained in detail,and how to complete the camera display.On this basis,the camera experiment is carried out by using Halcon software,and the display parameters are obtained.(3)Completed the algorithm development of the vision system based on the Halcon software development platform.Through comparative experiments,grayscale stretching transformation and median filtering were used for image enhancement operations finally.The method based on Blob analysis and IRLS curve fitting is used to realize the identification of the screw hole position.The maximum offset of the center pixel coordinate is 1.006 pixel,and the recognition accuracy is reliable.The deviation principle and the corresponding compensation method in the disassembly process are analyzed.At the same time,the relative motion method of monocular camera is used to realize the positioning of the actual coordinate position of the screw hole.Optimize the internal disassembly sequence of Honor 6 mobile phone,the optimal path length is413.12 mm by genetic algorithm in MATLAB software.(4)Based on the modular and hierarchical design ideas,the upper computer software of the screw automatic disassembly device is designed.The framework of the software is divided into human-computer interaction layer and application execution layer.Based on this framework structure,a human-computer interaction interface was developed.Taking a single screw disassembly step as the process template,the continuous disassembly movement is realized by constructing the Access database.