| In the process of electronic products processing,the welding of printed circuit board(PCB)is a key link,and also a relatively time-consuming production process.At present,the welding of plug-in components for double panel in industry can not effectively improve the degree of automation,but try to replace pin components with patch components.But so far,plug-in components still occupy a certain scale on PCB board.Therefore,it is very important to develop a device that can realize automatic welding of plug-in components on double panels.At present,the automatic soldering machine has not attracted enough attention to the automatic path planning of solder joints.Especially for PCB boards with large number of solder joints,how to optimize the path efficiently directly affects the soldering efficiency of the automatic soldering machine.The main research work of this paper is as follows:(1)Aiming at the problem that the convergence of the existing genetic algorithm is poor and its crossover operator is blindness,the convergence ability of the algorithm is greatly weakened in the later stage.In this paper,an improved genetic algorithm based on full combination paired reproduction strategy and bounded crossover operator is proposed.That is,by expanding the size of the offspring generated by each iteration to improve the probability of generating excellent individuals,and by limiting the crossover position to the non-common sequence segments of two individual chromosome sequences as far as possible,the efficiency of crossover operators can be improved and the blindness of traditional crossover operators can be reduced.(2)The path planning problem of automatic soldering machine can be directly regarded as the path optimization problem of all solder joints on PCB board.After analyzing the characteristics of solder joint distribution on PCB board,this paper proposes a grouping strategy based on adjacency table,that is,before searching the shortest path of all solder joints on PCB board,the solder joints are divided into several groups according to their distribution characteristics.Then coordinate quadrant method is used to calculate the distance matrix between groups.According to the number of groups,improved genetic algorithm and ant colony system(ACS)algorithm are used to search the shortest path for each group.Finally,according to the search sequence,the adjacent groups are matched with the best connection points,and then the shortest path search is carried out for all the solder joints within the group.The selection of the search method depends on the number of solder joints in the group.If the number of solder joints is small,the exhaustive method is used;otherwise,ACS algorithm is used.(3)In order to realize the automatic control of soldering equipment and improve the real-time performance of the system,this paper will divide the whole control system into two parts: the lower computer and the upper computer.The lower computer mainly realizes the precise control of the position movement of the moving platform,the on-demand spraying control of the tin spraying equipment,the image acquisition of the PCB board and the information communication function of the upper computer;the upper computer mainly completes the receiving of the data from the lower computer and the simple or complex data processing according to the received data type.In addition,in order to realize the control and monitoring functions of the upper computer,it is necessary to design the control interface and the monitoring and query interface.Through the cooperation between them,the automatic control function of soldering machine can be completed. |
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