Research And Development On Control System Of Friction-drived Conveyor For Automobile Assembly Line

With the continuous improvement of human cost in production system,material conveying system has been increasingly exposed problems,such as efficiency,flexibility,energy consumption.Friction-drived transmission system,using more than one small power motor,which forms a rally drive mode,is one of them.It has replaced the traditional method,using single powerful motor to drive the whole conveyor line drive,with excellent advantages of low cost,environmental protection and energy saving,flexible structure,convenient maintenance.Two important questions in friction-drived transmission system are synchronous control strategy of multi-motors and conflict avoidance strategy of multi-conveyor-lines.Firstly,this paper analyzed the system structure of industrial centralized,distributed and fieldbus control system and the advantages and disadvantages of them,and put forward the use of fieldbus technology to form a PROFIBUS-DP control network to realize centralized control system based on PLC,and completed system structure layout;Secondly,the basic principle of variable frequency speed regulation technology are analyzed.Through the comparing the control performance of the two kinds of basic control mode,this paper selected vector control mode to realize speed regulation of single motor,and on this basis established a mathematical model to make multi-motors be equivalent to single motor as the realization of single inverter synchronous control strategy of multi-motors;Thirdly,with the thought of transmission system is similar in each motor control function,the motor control was programmed as a separation of master control program and control function module.This chapter focused on type of conflict resolution strategy of multi-conveyor-lines,and configured the I/O address.PLC program of main function modules are given;Finally,on the basis of the touch screen,which embedded a configuration development environment,and PLC communication connection,the PC monitoring system of transmission system was designed.PC monitoring system can realize the function of real-time status display,transportation operation parameters setting,conveying system equipment debugging and conveying system alarm information display,etc.At the end of this article,the research work and the results obtained are summarized,and the friction-drived transmission system of the control system structure was further prospected.